Episode 3.02 - Pro Per. When a former con is arrested, he acts as his own lawyer and proves to be smarter than he appears. He shows up at the lab, asking to see some important evidence. Calleigh tries to stop him but the con, who is way taller and heavier than her, insists rather brassly. Eric witnesses the confrontation and comes over, gets in between Calleigh and the con and threatens him to use physical force if he doesn't leave. The con man leaves reluctantly, and Calleigh turns to Eric and snaps at him for coming to her rescue. Eric thought she needed a little help, but Calleigh insists he undermined her. Later on, as Calleigh questions Eric about the evidence he is processing, he humorously asks her if she's undermining him. Calleigh smiles and apologizes for snapping at him early on, and admits he was right for coming over to help her. They smile at each other and continue working on the evidence.
Episode 3.04 - Murder in a Flash. Eric and Calleigh investigate a "flash mob" where someone leaves the victim on a golf course. The situation with the students at the school is no better. Seeing the kinds of things the kids do in school, Eric reflects on how he was in school and considers himself an angel compared to the guys at the school.
Episode 3.07 - Speed Kills. Eric and Calleigh join forces to play a joke on Ryan. It's the first time we see them laugh together since Speed was killed. It's also impressive that Eric knew what Calleigh was doing without her having to prepare him for the joke.
Episode 3.23 - Whacked. The tension between Eric and Ryan is in full bloom, and Calleigh is forced to play mediator between the two. Later on, when Eric and Calleigh are alone, Eric expresses his unhappiness that Calleigh always defends Ryan. Calleigh denies his accusations, reassuring Eric that he's the one she trusts "with every fiber of my being." Eric smiles and softens up considerably. This is a very important episode, as we learn that Eric is the only man in Calleigh's life that she trusts so deeply, due to the fact that she grew up with an alcoholic father and has gone through multiple bad relationships. Calleigh's admission of such an intimate thing shows how truly close these two are.
Episode 3.24 - 10-7. Disturbed by his ex-partner's suicide and his inability to have Calleigh, John Hagen's mental state is not well. He puts his gun to Calleigh's head while she is processing a scene, but slips away before she sees him. Eric finds her in the lab and helps her identify the gun. Before she can trace it to Hagen, he shows up in her lab and shoots himself in the head in front of her. Calleigh is in shock after witnessing this, and when Alexx comes to collect the body, she tells Eric that he may be the only one who can get through to Calleigh. Eric tries to comfort Calleigh, but the walls she's built around herself are hard to climb. Calleigh resigns as the ballistics expert at the end of the episode.
SCENE of E/C moment in season 3
Special Thanks to belluvsmiami2 and MimoriKiryu for provided the videos