The crew is dying as a duplicate ship falls apart.
Voyager celebrates the wedding of Tom Paris and B'Elanna Torres and a new warp drive that promises to bring them home within two years. Then systems fail and Torres dies as her cells break down. The crew discover that they are not the real Voyager crew but copies made of a biomimetic substance on the Demon-class planet they once visited, and the new drive is making them fall apart.
They look for another such planet to restore themselves, but Janeway refuses to fight a mining ship guarding the one they find, choosing her ideals over survival. As the crew die one by one, the survivors build a time capsule of their logs, but it fails to launch. Harry Kim, the last in command, ejects the warp core to send a distress call. The real Voyager arrives to find only traces of fluid in space. The fifth-season episode is a sequel to Demon and a sad story about memory and identity.