Last year, during the height of the coronavirus (COVID-19) pandemic, Touchstone Theatre debuted the first production in its “Letters from Far” series.

The innovative series was the ultimate in social distancing and unfolded its futuristic plot through tantalizing clues contained in packages sent in the U.S. Mail over several weeks.

This year, Touchstone is presenting a new entry in the mail-based series that goes back in time to the 1900s.

The southside Bethlehem-based theater troupe will soon be sending out episodes of the train mystery, “Shadows in Steam,” which will be delivered to audience members’ mailboxes Feb. 15 to March 21.

Emma Ackerman, Touchstone Theatre Ensemble Member and director of the “Letters from Far” project, says the concept was born as troupe members brainstormed ways to create artistic content that could be safely delivered in the midst of the ongoing COVID-19 pandemic.

One of the ways, the theater company responded to making socially-distanced theater has been by offering shows outdoors. But that wasn’t practical during the cold winter months.

“We knew that it was a challenge since it would be a while before the weather’s suitable for performing outside again,” Ackerman says. “We wanted to create content that people could enjoy safely in their own homes, while still experiencing theater in inventive ways.”

In the first iteration of “Letters from Far” that Ackerman and Touchstone Ensemble members created, the story followed the fictional Rosensweig Expedition sent in 2032 to explore a mysterious rift found in the American Midwest that is a portal to another world.

When the expedition party does not return, all that remains are the packages they sent home, including letters, drawings and artifacts from “the other side.” Recipients of the “Letters” were invited to read the final account of the party, in their own words, and piece together the last days of their journey.

“What started out as a sci-fi mystery story ended up manifesting into a piece about isolation, loneliness and a need to communicate and connect,” says Ackerman.

“So, even though it was a story about visiting an alien world, everything under the surface of the plot was very much rooted in things that we were going through as a community in the height of the pandemic.”

Ackerman is back again writing and directing “Shadows in Steam,” which is set in 1906 when a steam locomotive pulls into the station with three passengers dead, foul smoke puffing from the engine, and no explanation for a rash of nightmares among the crew.

Eyewitness accounts of what happened aboard the train vary, with reports of mysterious meetings, strange noises and seemingly supernatural phenomena.

The audience, i.e., those receiving the letters, will participate as friends of the investigating police officer in charge of the case, and will receive an introductory letter, written statements from the survivors and physical evidence from the investigation.

The production includes six small packages, arriving in mailboxes weekly in February and March, allowing ticket-holders to follow the story at their own pace as they dig into a pseudo-historical mystery.

As with the previous Touchstone production, ticket-holders receive packages stuffed with hand-written accounts, original drawings and even small artifacts that relate to the investigation.

“With this project, we wanted to focus on the ways we try to communicate the impossible to one another,” Ackerman says.

“In an era where so many of us are operating in different spheres of information and seemingly different realities, this theme feels all the more worthwhile to explore,” says Ackerman.

Deadline to register for “Shadows in Steam: A Letters from Far Story” is Feb. 1. Tickets are available per household and can be mailed to any address in the United States. Tickets are limited.

Tickets: www.touchstone.org; 610-867-1689

“Curtain Rises” is a column about the theater, stage shows, the actors in them and the directors and artists who make them happen. To request coverage, email: Paul Willistein, Focus editor, pwillistein@tnonline.com