Timeship commanded by
Captain Braxton, the
Relativity played a key role in saving
Voyager from being destroyed by a rogue time traveller.
Braxton recruited Seven of Nine to help him figure out who planted a deadly weapon on Voyager. It was eventually revealed that Braxton himself planted the weapon, and he was relieved of command by his first officer.
Like other timeships from the 29th-century, this Federation craft uses artificially-generated temporal rifts to journey through time.