Marcus marvels at Polis when the crew arrives for the negotiations in episode 3x03 "Ye Who Enter Here". Lexa battles Roan in episode 3x04 "Watch the Thrones". Octavia talks Indra out of her funk in episode 3x07 "Thirteen". Roan escorts Clarke into town to draw Ontari out in episode 3x15 "Perverse Instantiation: Part One".
Frank's car is pulled from the river with his body in episode 1x01 "Pilot".