Torchwood verse:

Archieva started to work at Torchwood 3, after the whole thing where she was forced to kill someone – that someone being Jack – basically aliens blackmailed her, held her family and friends hostage and forced her to poison Jack Harkness or they would kill them all and then the planet.

Jack saved the day like always, saved her mom/Dad and baby sister and then asked her if she wanted to come work as the archivist, along side Ianto so that he had a second pair of hands helping him through the decades worth of stuff and paperwork down there.

Archi’ agreed as the uni library had started to grow boring and now enjoys helping the team with everyday things and adventures, always knowing where information in the archive was or what knowledge might help at that moment.

(Of course there is also the fact that she is a Fobwatched Time Lady… not that she knows)