Messenger Particle is the second issue of the comic book series Savage Starlight.
On the second floor of the last house you see after exiting the sewers section, go inside the small bathroom. The comic is atop the tank of the toilet.
On the back of the book, a blurb summarizes the contents of the comic.
The first test of Daniela's zero-point jump drive started out a success, but contact with the test pilot was immediately lost. Forty-eight standard hours later, he returned transformed, and he came with a message. "WE ARE THE TRAVELERS," the message began.