Catch & Release

London, 1893. The morning post brings a letter about a room that is always cold, a teacup that rattles on its own and a lamp nobody lit. Take the case, read the house, and give the ghost its proper name.

You are new field staff at the Museum of Spectral Taxonomy, where Cordelia Voss has spent her life sorting the dead by the senses they haunt. The museum is your hub: a cab rank in the fog, a Main Collection of 437 bell jars, a basement organ that makes the jars answer, a library of scent vessels, and a grandfather clock whose ghost insists it runs three seconds slow. Aldous Finch, Mrs Pratchett and Helena Voss keep the place running, and the ghosts glow cobalt blue, the only color in a sepia world.

With up to three friends you ride the cab to a house and sweep it with brass instruments. Find the cold that sits exactly 4.7 degrees below the room, strike a tuning fork and listen for an answer, photograph what the eye cannot see, and tag each reading genuine or draught. When the evidence agrees on phylum, class and routine, you file the label and a second player countersigns. Then decide: bank the photographic plate at the cab now, or stay and finish the ghost's task, setting the last teacup or lighting the last lamp, and watch it complete its routine and fade.

The monster is doubt. Every reading you dismiss and every wrong name feeds Specimen 848, a white hole in the picture that grows on disbelief. When the crew's shared doubt reaches halfway a white seam opens; push it further and 848 hunts, blanking people into empty white outlines. Nobody dies: a mirror or a teammate's photograph brings them back into color. The safest crew is the one that believes what it sees.

The first release has three houses, each with four ghosts to release and four more to file: Wren Row, a lodging house worked from the basement scullery to the box room; Halcyon Terrace, a house in mourning where Mrs Dalrymple's table is still laid; and Turnmill Lane, a foggy street block where a lamplighter still walks his round. That is 24 ghosts, sorted into five phyla, one for each sense. Cases are for one to four players, and solo play is complete.

Your plates hang in your own cabinet in the museum, a gold-edged Completed plate for every ghost you release, and released ghosts come back to visit. New letters arrive each day with a featured specimen, Mrs Pratchett serves tea once a day, a new pair of ghosts joins every fortnight, and the yearly Night the Jars Break turns the whole museum into one great release. Nothing decays and no reward expires.

Based on The Taxonomy of Ghosts by Chisato Funabashi: the five phyla, the 4.7-degree constant, the exact lure frequencies and the rule that a ghost rests once its routine is finished come straight from the novel.

Catch & Release is a finished game design for Roblox that Greenlight Games plans to build in-house.