Your description of Tanya's abuse is horrific but economically so; it's the lack of details that make it so much worse.
Then Rock's perversion of a rescue that poisons Frank's genuine attempt that gets shortcutted by the not-so-small issue of the collapsing, burning building. But all that makes his coaching of her outside all the more tender and beautiful. Frank rescues her on so many levels while her prison and abusers burn (with the distance in *bed* lengths!).