The Tartarus Key Walkthrough: Save Everyone and Reach the True Ending

Full spoiler warning: this route names every captive, gives puzzle answers, and explains all three endings.

The most expensive mistakes in The Tartarus Key do not happen at a keypad. They happen after a rescue puzzle, when a plausible answer is accepted and a captive dies. The mansion keeps moving, so the consequence can look like ordinary story progression until the final door produces the Bad Ending.

This walkthrough treats the game as one survivor chain. Alex must help Torres, Charles, Ruth, William, and Kai before opening the lower complex. It then creates one clean branch for the Good Ending and True Ending. Use the room map, examine both sides of documents, and save before every life-or-death interaction. Codes are included, but the clue that proves each answer is included too, so a rotated camera or differently worded prompt does not turn the route into guesswork.

Build three save points around irreversible choices#

The game supports manual saves, and this route needs three roles rather than one file that is continually overwritten:

Do not use the rescue-safety slot for the ending branch. A wrong antidote, ritual, drink, or computer instruction can close the survivor route long before Reception. After each rescue, confirm that the person returns to the Great Room. If a scene ends with an empty place where a survivor should be, reload immediately instead of hoping the ending logic will forgive it.

Escape the Office and free Torres through the wall#

In the Office, collect the four postcards and inspect their backs. The digits alone are not the order. Open the desk drawer with the key from the large cabinet, then use the travel record to arrange the postcard numbers chronologically. The safe code is 7341. Take the door key and continue into the Bedroom.

The Bedroom asks for five colored bottles. The torn bottle paintings show which colors sit toward the white center bottle. Facing the row, place them black, yellow, white, red, green from right to left. If the drawer does not open, first check that the white bottle was collected from the paintings on the floor; it is easier to miss than the bottles sitting on furniture.

Follow Torres’s knocking to the locked door, then enter the bloodstained Bathroom. Two footprints face the mirror. Stand on them and line up the reflection until the bloody message resolves. Inspect the painting indicated by the mirror, take the hatchet after the scene, and use it on the cracked wall behind that painting.

Do not use the hatchet on Torres’s door for the survivor route. The door is the tempting direct target; the damaged wall is the correct rescue path. Once Torres is safe and the pair reach the Great Room, open the map. It is not decoration: Alex adds rooms and annotations as the mansion changes, and several late optional locations matter to full-map cleanup.

Charles’s route is a chain of identities, not random symbols#

From the Great Room, take the ground-floor route to the Library. Read the murderer books before touching the weapon case. Each weapon represents one killer, and their active periods determine the button order. The case sequence is 4, 2, 1, 3, 5.

The opened case gives you statues with numbers on their backs, while the new painting selects three weapons. Use those two clues together on the sliding bookshelf: the top shelf corresponds to the hammer and needle marked 1, the middle to the watch marked 5, and the bottom to the paintbrushes marked 3. Think in terms of the selected book positions, not a memorized number of clicks; counting moves from an unknown starting position is a common way to overshoot the shelf.

In the Gallery, activate all five buttons so the statues and lectern can be read as one diagram. Match each mural figure to its planetary-looking symbol:

• Angel: the horned stick figure.
• Minotaur: the triangle with two lines below it.
• Lamia: the double-Z mark.
• Knight: the crescent moon.
• Demon: the figure with a small circular head.

The Lounge contains Charles and five sigils, including one decoy. Find the marks on the room’s surfaces and have Charles identify them before placing anything. The journal describes a creature or image in each direction; the demon descriptions convert those images into names. Set Andromalius north, Bifrons east, Raum south, and Malthus west. Leave Furfur unused.

Make the rescue save before confirming the ritual. A wrong layout still advances the scene but loses Charles. The success signal is Charles leaving the Lounge alive and joining the group.

Use the Closet as the route into Ruth’s Clinic#

Return toward the East Wing and open the lion-marked route. The Closet has four locks that use four different clue languages. Repair the broken wire with the red tape before reading the first keypad under blacklight. Patch V01.01b added sparks to make that wire more visible.

1. Enter 2940 on the keypad.
2. For the card-suit lock, enter spade, heart, diamond, spade, diamond.
3. For the colored three-by-three grid, enter the rows as B-P-P / Y-Y-P / P-B-Y, where B is blue, P is pink, and Y is yellow.
4. Rotate the final circular design into an upward triangle with an eye near the bottom. Treat the finished picture as the target, because ring starting positions are easier to verify visually than by copied click counts.

Take the Appointment Card and follow the revealed footprints. In the Clinic, the button beside the organ drawer changes the dials. Assign the visible controls numbers in ordinary reading order, then press 3, 2, 3, 3. Collect the model heart plus the liver, lungs, and stomach from the drawers, place every organ in the anatomy model, and take the brain. Putting the brain in the specimen jar moves the skeleton; complete its pose to open Surgery.

Ruth’s antidote uses one ingredient you must separate#

Surgery is another fatal checkpoint, so save before mixing. Collect the needles and the available chemicals. The distinctive scratches beside the bookshelf identify a movable section; shift it and inspect the hidden body to obtain the found antidote and its note.

Draw Ruth’s blood with the needles. The books indicate that Tau is required, but the loose bottles do not give you usable Tau. Put the found antidote through the centrifuge to separate the Tau blue chemical. At the beakers, combine:

• drawn blood,
• Tau (blue),
• Alpha (red).

Stop there. Adding an extra chemical because an open slot remains creates the wrong treatment. Inject the resulting antidote only after checking the three-part list. Ruth surviving and returning to the Great Room is the confirmation that this branch remains valid.

Turn the Master Bedroom clues into William’s drink#

Go upstairs to the Master Bedroom. Close and inspect the cabinet to expose the starting digits, then use the four projected swap diagrams around the room. Applying them in numbered order transforms the sequence into 1925, which opens the concealed room.

Insert the new slide. The three dresser columns should finish on row 3, row 3, and row 2. Take the next slide and the statues. On the projection board, keep all three statues in the middle column: short at the top, medium in the center, tall at the bottom. Their shadows form a door. Return to the hidden room and take the newly opened path to the Planetarium.

Planetarium dates and directions

The console needs a date at each compass position, followed by that side’s lock switch. The notes use different date conventions, so 08/03 is not interchangeable with 03/08.

Lock each side after setting its date. The Peacock Key is the success signal. In the looping corridor, continue until the route repeats, backtrack a few steps, then try the passage again to return to the Main Hall. Use the Peacock door to reach William.

Inspect the nearby portrait and move the rug. Rotate the circuit tiles until every edge terminal is powered; the blue edge lights confirm a complete network. With the illuminated grid oriented so its arrow points up, combine the partial marks indicated by William’s journal. The resulting safe code is 5423.

Save before serving the drink. Take the empty bottle and coffee beans, collect dirty water from the vase, and filter it before brewing. Build the Gumshoe with two measures of fresh coffee, followed by one measure of whiskey and one of apple liqueur. Warm the completed mixture at the fireplace. “Piping hot” is a final step, not a reason to pour unfiltered water or add coffee after mixing. Give William the hot Gumshoe and verify that he survives.

Do not start Kai’s countdown until the Lab is searched#

The bloodstained route into the lower wing opens after the earlier branches. In the Lab, collect the clean cloth and lighter before committing to the central controls. Wipe the blood on the floor to make a DNA sample, then use the control panel. The failed authentication opens another locker; take the ID card and screwdriver.

Use the ID to stop the purge. Open the panel below Kai’s vat with the screwdriver, tamper with the exposed sensor using the lighter, and return to the main controls. The trick is to make the system read the occupied vat as inactive, not to defeat the DNA check by repeating it. If the countdown is running and you do not have the ID, screwdriver, and lighter, reload rather than searching under pressure.

In the Pantry, move the painting named by the note. Count the circled objects: six paintings, three mops, two brooms, and two skeletons. That gives 6322.

The Cold Storage is a sliding-block puzzle whose goal is the meat rack with red tags, not an empty exit square. Use the ceiling grid to preserve orientation. Clear the racks directly in front of the target, move the tagged rack forward, then consolidate the lower-right blockers to the left and the upper-right blockers downward. Shift the target right, clear the upper lanes, and finish by moving the tagged rack right, up, left, up into the saw. If that final pattern is impossible, an earlier blocker is still occupying the upper corridor; do not reset until you have checked that lane.

Kitchen burners and Kai’s three tests

Use the Kitchen Key, collect all six recipe cards, and compare them with the weekly menu. Friday is the only menu day that can be built from the available recipes: Chicken Madras and Beef Stew. Install the gas valve, then set:

• Left stove: light the two burners on its right-hand side and lower its basket.
• Right stove: light every burner except the upper-right one and raise its basket.

Save after reaching the Holding Cells and before confirming the computer prompts. One wrong instruction electrocutes Kai. The three answers are:

1. Direction path: up, right, down, down, right, right.
2. Letter path after the starting B: C, D, A, C, B, D.
3. Suit destinations after the starting spade: heart, club, spade, heart, club, spade.

The clues explain why. The first route is hidden in the tally marks. For the second, only one printed letter string can be walked on the grid. For the third, a spade chooses a heart when no diamond is available, a heart beside a spade moves to a club, and a club cannot choose heart or club. Kai returning alive completes the captive chain.

Audit the Great Room before entering Research and Development#

Before approaching the mansion’s apparent exit, count the living group: Torres, Charles, Ruth, William, and Kai should all be present. If one is absent, the lower section can still progress, but the Good and True endings are already closed. Reload the relevant rescue save now.

When the full group is assembled, trigger the exit scene and enter Research and Development. Pick up the four toy swords. The room gives one positional clue for each colored side of the toybox:

• green wolf side: bottom slot,
• blue bird side: lower-left slot,
• red unicorn side: upper-right slot,
• yellow whale side: bottom slot.

Take the clown’s note after the box opens. Its blue-and-yellow book diagram identifies the book to pull beside the door. Continue through the subject area, talk to the group, and take the Admin Keycard when the story provides it.

In the Control Room, collect the cables and compare the checked monitor positions on the whiteboard with the colored displays. The three white servers need to become pink, orange, and green from left to right. Connect left white to red plus blue, center white to red plus yellow, and right white to blue plus yellow. Once the central computer is available, continue through the Meeting Room to the Director’s Office.

Take the TV remote and cycle the Director’s screen until the highlighted brick arrangement appears. Match that arrangement to the three small paintings above the couch, then interact with the matching left painting to expose the exit control.

Branch at Reception, not earlier#

Make the ending-branch save before returning to Torres. This is the reusable state for the two survivor endings.

• Answer Yes when Torres asks whether the group should leave to see the Good Ending.
• Reload the ending-branch save and answer No to keep investigating for the True Ending.
• If any captive died earlier, leaving produces the Bad Ending. That outcome cannot be repaired from the Reception save because the failed rescue is already part of the state.

The official description confirms three endings, but it does not make three full playthroughs necessary. A clean survivor run plus the Reception branch covers both non-failure endings. Keep the separate pre-rescue save only if you deliberately want to revisit fatal choices later.

Use the Director’s image to locate the Hidden Crypt#

After refusing to leave, return through the sub-basement and take the elevator to the Cellar. The barrels reproduce the highlighted-brick image from the Director’s Office. Inspect the barrel occupying the glowing position to open the secret passage. Written references disagree on whether to call it the second barrel from one side, the third from the other, or the second from the end; the TV pattern is the reliable in-game check.

In the Hidden Crypt, collect the angel, death, and gargoyle statues. Check the visible pedestals, the dark corner around the angel, and the coffin area before starting the dials. Place the angel on the coffin pedestal and copy its three revealed marks onto the right dial. Place death and copy its marks onto the left dial. The gargoyle inscription is unreadable, so the middle dial takes the three symbols not used by the other two. The coffin moves when all three columns are consistent.

For Cartographer cleanup, open the map after descending into the newly exposed crypt. Earlier easily missed rooms include the East Stairway, both bathrooms in the lower office complex, and the Subject Room. The True Ending area is part of the map, so the achievement cannot complete on the Good Ending branch alone.

Take the handle near the grave slab in the Sealed Crypt and fit it to the wall mechanism. Descend to the Cave Lake. The final laser board uses straight, corner, and three-way sigils. Facing the lake, arrange the connection types like this:

corner   three-way   corner
three-way corner
corner   straight    corner

Then rotate the pieces until each row carries light into the central pedestal. Judge the solution by continuity: every incoming beam must leave through a connected notch, and three completed lines must strike the center. A correct network creates the path across the lake.

The last sequence deliberately echoes earlier rooms. In the Bathroom replica, look into the mirror, turn to the painting, and check the mirror once more. In the Surgery replica, take the bone saw and use it on the marked wall. In the Lab replica, leave the room and continue through the corridor door. Walk up the final staircase when control returns. If the entire group survived, this route reaches the True Ending.

Sources and credits#

Game identity, release metadata, the three-ending premise, and screenshots were checked against the official Steam page and the Armor Games Studios game page. Room order and puzzle results were independently compared across several readable player-written references. Every image is an original official Steam screenshot for AppID 1431850.