Two past verbs together

Hi, first of all, I must apoligize for my level of english, I'm learning it, and at the present, isn't very good, my question is about a phrase of the Stephen King's book Under the Dome. There appears this: "Searles had gone at her hard, and although she tried to remember what she and Dodee
had done two days before, it didn’t work. She remained as dry as August with no rain. Until,
that was, what Carter Thibodeau had only abraded ripped wide open"

Why there is two verbs in past put together,? is a common formation

Thanks