Very stealthily we heard it pass along until it died away in the distance. Then the baronet gently opened his door and we set out in pursuit. 

Already our man had gone round the gallery and the corridor was all in darkness. Softly we stole along untii we had come into the other wing. 

We were just in time to catch a glimpse of the tall, black-bearded figure, his shoulders rounded as he tiptoed down the passage. 

请教老师：We were just in time to catch...中什么结构？just in time是状语吗？ 如去掉分析，则为We were to catch...were to结构怎么理解？

主要是不懂 were just in time to 这一结构？