Barry goes to stop a high-rise fire where Captain Singh's finance is trapped in episode #120 "The Trap".
Dr. Wells reveals that he has known about their plans all along in episode #120 "The Trap".
Oliver goes to meet Moira in front of their company headquarters when she is shot at by a mysterious individual in episode #107 "Muse of Fire". Museo and Oliver see Thea outside the building in episode #314 "The Return".
Count Vertigo is being transported from the courthouse when his guard is injected with vertigo and begins shooting at press in episode #313 "Canaries".
Laurel talks with the others on the phone from Starling City in episode #303 "Corto Maltese".
Philip is leaving a building when he spots Detective Gower waiting for him in episode #101 "Travelers".