The search begins is an article in Resident Evil Recollections. It was uploaded on 21 July 2015.
Just after the intro to Resident Evil Code: Veronica, Claire's jailor Rodrigo, the very man who captured her, suddenly unlocks her cell and tells her to escape.
It's hard to say what his motives are early on, but it later becomes clear that he's grown tired of being a yes-man for Umbrella and he wants to save what little honor he might have left.
As the beginning of Resident Evil Revelations 2 was meant to be a throwback to Claire's past, you'll notice how the prison doors open themselves without her intervention again. She's probably thinking it's about time people stopped kidnapping her if all they're going to do is set her free again...
Anyway, now that Claire has been freed, it's time for Resident Evil Code: Veronica to begin!