{Were waiting for us in Troas} (emenon h(886d)(8373) en Troiadi).
Here again we have "us" for the first time since chapter 16 where
Paul was with Luke in Philippi. Had Luke remained all this time
in Philippi? We do not know, but he is with Paul now till Rome is
reached. The seven brethren of verse  4  went on ahead from
Philippi to Troas while Paul remained with Luke in Philippi.