BALTIMORE (AP) — For a few hours each month, Katie Carlin, Olivia Curié and Sean Greening are no longer roommates persevering through a pandemic.

The arrival of a box on their Riverside doorstep transforms their house into a private detective agency, as the three sleuths scour the enclosed maps, letters, autopsy reports, crime-scene photos, items of clothing and other evidence for clues — and dodge red herrings — to solve an imaginary murder.

Carlin, Curié and Greening are among 100,000 people across the country who now subscribe to Hunt A Killer, the fast-growing series of murder mysteries from a Baltimore-based company that players gradually unlock using physical clues that come in the mail each month.

For $25-$30 a month, depending on the subscription, Hunt A Killer creates an “immersive experience,” similar to an escape room, in the comfort of players’ homes. Up to six players work through the evidence to determine each suspect’s means, motive and opportunity to commit the crime.