Shaw briefly appears, largely off-camera, talking with General Beckman in the third season episode, "Chuck Versus the Three Words".

In "Chuck Versus First Class", Shaw tells Sarah that he was once married to a fellow spy, Evelyn (later played by Kelly Thiebaud), but that she was killed by a Ring agent five years before.

In "Chuck Versus the Mask", Shaw begins expressing a romantic interest in Sarah, which she initially and strongly rejects.

However, despite initial attempts to kill Shaw, the Ring opts not to target him when they lure him out of Castle and have him "dead to rights" in a setup.

While in the Ring's custody, Shaw is played a surveillance video of his wife's death, revealing that Sarah killed Evelyn as part of a "red test."

In "Chuck Versus the Living Dead", Shaw is revealed to be alive, and downloads the Ring's Intersect prior to the end of the episode.

In the next episode "Chuck Versus the Subway", Shaw discredits the team by fooling them into storming a hearing between Beckman and a military panel over the fate of the Intersect project.

Shaw intercepts them and steals Chuck's Governor, a device designed to protect the human Intersect from going insane, and fatally shoots Stephen.

Shaw planned to upload and erase the CIA's database to create a new Intersect 3.0 so that they would be forced to rely on him for intelligence and so that he could defeat Chuck even more easily.

[5] In addition to the conflict between Chuck and Sarah, Josh Schwartz and Chris Fedak have indicated that Shaw's presence will also affect Casey, due to his orders to assume command of the team.

[6] Routh describes Shaw as the government's foremost expert on the Ring, and that this was among the reasons of his assignment to Team Bartowski.

Although generally portrayed as cold and emotionless, Shaw is still highly sensitive where his wife is concerned and reacts angrily when shown footage by the Director revealing that Sarah killed Eve.

Ultimately, these lingering feelings for his wife lead to his downfall, as the Director uses his anger and grief to turn him to the Ring by playing on his single-minded desire for revenge.

This desire is initially directed against Sarah, but following the events in Paris Shaw has shifted the focus of his hatred onto Chuck instead.

He nonetheless warns Sarah that he would still greatly enjoy the opportunity to kill her, but sees her demise as more of a bonus than a necessity.

Throughout his presence on the team and later as an antagonist, Shaw often disparages Chuck's strong feelings for Sarah, his friends, and his family, and expresses a belief that emotional connections are a liability and get in the way of being a good spy.

In "Chuck Versus the Santa Suit", Shaw becomes a purely villainous character; he murders two guards escaping from prison, kidnaps Sarah, shoots Casey and admits to be a criminal mastermind behind the Omen Virus Operation.