Catalysis is the thirteenth issue of the comic book series Savage Starlight.
After swimming under the bus to drop a ladder for Ellie, you will be near some vents. Walk along them until you reach the end of the shaft - the comic will be lying on the ground at the edge.
On the back of the book, a blurb summarizes the contents of the comic.
Faced with the failure of their mission, Daniela and James chose to make the ultimate sacrifice for humanity: flying the ship, and the anticarbon bomb on it, straight into a neutron star.
The resulting explosion was the single most significant astronomical event since the formation of the galaxy, destroying the Traveler fleet, their homeworld, and countless other worlds and star systems. But will the sacrifice of two of humanity's greatest heroes be enough to break the Travelers' iron grip?