Key & Compass presents:
by Hugo Martay

Causality is a Z-machine 5 interactive fiction game written with Inform 6 and is © 2003 by Hugo Martay.

You play as someone who hops around the space-time continuum, witnessing or interfering with human history. Sometimes you witness destruction. Sometimes the destruction is caused by your own hands. Are you an agent of a higher power? And what effects will your actions cause?

This solution is by David Welbourn, and is based on Release 2 of the game.


Note 1: This game consists of a series of small scenes, set in order like a string of pearls. Although your identity, physical body, location, and the year will change between scenes, sometimes you keep your inventory items regardless. Sometimes, items from a previous existence are needed to solve a puzzle in a future existence; be warned.

Note 2: You get to cause an impressive amount of destruction in this game. Frankly, it gets a bit surreal when you pop into a new place in the space-time continuum and just know you're going to destroy it all in fairly short order.

Part 1: Earth

u Hilltop Street meadow d


We begin with the end of the world. Your objective: die. No, really. You can do what you like for eight turns in this section, but if you want more info, find the proper newspaper and read it before you die.

> x star. x people. d.


> x dog. x house. s.


Yes, of course there's still newspapers in 2097. And you probably don't really want to know what the improper newspapers are like.

> x proper newspaper. x tabloid.

Part 2: The Mars 24

u sleepingquarters The Mars24 Narrowtunnel. lifesupport Airlock d cut wire

The Mars 24

Reading the note tells you your new mission: destroy your spaceship. CAUTION: Don't cut the wires until you have the cable.

> i. x note. take knife. x it. x wires. search wires.

> x cable. take cable. x computer. x window. d.

Narrow tunnel.

> n.

sleeping quarters

> s. s.

life support

> x fan. x life. x wires. cut wires.


> z. z. z.

Part 3: Antarctic Research Base

Biolabs SleepingQuarters Hub Communi-cationsroom TelescopeRoom


New identity; new note. Mission 3: destroy the biolabs.

> i. x note. u. w. open blue door. s. open green door. e.

Communications room

> x radio. take it. put cable in it. w. n.


There's no in-game way to tell that the green vial is the important one, but y'know, there's only three of them...

> x cabinet. look in cabinet. x green vial. x blue vial. x purple vial.

> x microscope. look in it. x battery. take it. put it in radio.

> x radio. x computer.

> take green vial. open cabinet. break it. take all vials.

> break green vial. throw green vial.

Telescope room

You haven't gone far in space.

> i. x computers. open door. n. n.


> take radio. s.


> open blue door. w.

Sleeping Quarters

Tom isn't very talkative, but what else is there to do?

> x Tom. x Natalie. x bed. x window.

> x desk. open desk. take diary. read it.

> ask Tom about radio. tell Tom about green vial.

Sleeping Quarters

Same place, different time.

> l. i. x radio. e. n.


> x Natalie. ask Natalie about green vial. ask Natalie about MN390.

> s. s.

Telescope room

> x computers. z. z. z. z.

Part 4: Interlude

MedicalBay Room Liferaft MotorBoat


Well, you've released a deadly biological virus, and your coworkers are dead or dying...

> x newspaper. x radio. z. z. z.


...and now, you get to release a computer virus on a nuclear warship.

> i. x note. x cd.

Motor Boat

> x marines. z.

Part 5: The SAS Anatoly

u u u u (deck) (controlroom) (munitionsroom) (kitchen) (storeroom) d d d d Bridge Stairs.East.P deck. Stairs. West. P deck.You can go outsideto the east. MissileDeck Stairs.East.A deck. Corridor.A deck.West Side. Corridor.A deck.Central. Corridor.A deck.East end. Stairs.West.A deck. Centralcomputerroom Stairs.West.B deck. Corridor.B deck.West side. Corridor.B deck.Central. Corridor.B deck.East side. Stairs.West.B deck. FoodHall MedicalBay Crew'sQuarters

Medical Bay

> x table. x doctor. n.

Corridor. B deck. Central.

> e. e. u. w. s.

Central computer room

The virus doesn't upload until you look at the computer with the CD in it.

> x computer. put cd in it. x computer. n. e. u. e.

Missile Deck

> x launchers. z. z. z. z.

Part 6: Underwater and Ark1

u u d d Under-water Outside ofCapsule In theSea Airlock Under-water Ark1 livingcapsule


> u. swim. z.

In the Sea.

Buh-bye, ship.

> x ship. x radio.


> z.

Ark1 living capsule

Time to destroy a second spaceship.

> x note. open internal door. u.


Good save with the instant spacesuit, eh? Brother.

> close internal door. open external door. u.

Outside of capsule

It's not easy to refer to the plutonium source in the engine. Fortunately, you don't have to.

> x warhead. search it. x detonator. x plutonium warhead. take it.

> x engine. search it. x thruster. x shield.

> take shield. put plutonium warhead in engine.

Part 7: Mars Dome

enterrover DockingBay. OutsideMartianBase. Maindome,mars planningroom (any dir.) wilder-ness

Main dome, mars

> x radio. s.

planning room

Shame the map isn't presented in a monospaced font.

> x charts. x map. take it. n. n.

Docking Bay.

> x rover. enter it.

Outside Martian Base.

Your fuel goes down with every turn, but the game fails to check if you run out. Don't go into the rifts on the map; they'll make you lose the game. By the way, the ship has not landed at the expected spot; you'll have to use the radio (finally!) to find out where they really are.

> x radio. s.

Part 8: Mars Wilderness

1 2 3 4 5 6 7 8 9 10 1 rift rift ok ok ok ok ok ok ok ok 2 ok ok rift ok rift ok ok ok ok WIN 3 ok BASE ok rift rift ok ok ok ok 4 ok rift ok ok ok ok 5 rift rift rift 6 ok ok ok ok ok ok ok rift rift rift 7 ok ok ok ok ok ok ok rift


> e. e. s. e. e. e. e. e. e. n. n. n.

*** You have won ***

Hey. Don't we get to blow up Mars, too? Darn.

Thank You to my Patreon supporters

This walkthrough is provided free of charge since I wrote this walkthrough prior to January 2015 when I began my Patreon account. I've since reformatted this walkthrough to use my currently preferred style. I hope you enjoy it!

I'm still creating new walkthroughs! Please visit my Patreon account if you're interested in helping me create more interactive fiction walkthroughs. I appreciate all the help I can get! Thanks again.