There was, unsurprisingly, a cameo from Oliver Queen in this first episode, although it was perhaps a slight surprise to see that he still had Ray working for him, given it hasn't been mentioned on the main show. The appearance of Laurel Lance was less expected, but the training scene between her and Sara was a nice touch, and the most likeable that Laurel has appeared in quite some time. With both of the Arrow recruits being represented by main show members, then, it was weird not to see any of Team Flash show up, in particular Barry Allen. When Oliver appeared I naturally assumed The Fastest Man Alive wouldn't be far behind, but then there was no sign of him. It's not 100% clear where this fits in with what we've just watched on the other shows, but perhaps he was too busy with his own relationship drama?