Eve is in disguise trying to leave the city when she is approached by a mysterious woman from the organization that hired her to infiltrate Lex's operation in episode 4x22 "The Quest for Peace".
Kelly stops Alex on their way to game night to confess feelings and they kiss in episode 4x22 "The Quest for Peace".
Izzy joins Jack on a bench and they reminisce about the past before getting a distressing text from Emma in episode 2x10 "Baby, Baby Where Did Our Love Go?".
Source: What's Filming
Jack and Izzy discuss Emma's mysterious return on their way to dinner with Izzy's father in episode 3x06 "Fool Me Once? Shame on You. Fool Me Twice? Blow Me".