Steve Finch burst into her room. (Para. 2)
Meaning: Steve Finch rushed into her room without knocking or warning her in advance.
burst into:

(1) enter hurriedly or explosively
The children burst into the room looking for toys. 孩子们冲进房间找玩具。
(2) start suddenly
She burst into laughter. 她突然大笑了起来。