Her starting to realise she was losing herself was kind of devastating.

YES, OMG, IT SERIOUSLY WAS. It totally wrecked me, augh. Plus aaaaahhhh, refusing the drink -- I spent most of the summer in a state of HO SHIT WHAT ARE WE GONNA DOOOO and hoping that the first thing that happened was Peter realized it wasn't Oliva, but I'm so so glad they did it this way, because hanging out in Alt!Verse for an entire episode is always so fun. Plus Anna KILLED IT.