S5·E11 Fire in the Hole

Wade shows up with Dan Gabriel, his old commanding officer in Vietnam, who's now a covert operations/demolition expert. Dan and Grace begin a verbal sparring match almost immediately. He's a warrior and a hard-core conservative, and Grace hates everything he stands for. Later, Dan has no trouble winning over Jean, and he talks to Libby about how to use psychological intimidation to defend herself against a bully who put gum in her hair. An angry Grace tells Dan to keep himself and his violent approach to life away from her kids, but their conversation ends in a passionate kiss. Grace is horrified that she's madly attracted to a guy she hates, and it's obvious that Dan's equally attracted. But Dan dives into the river to do some demolition work for D.C. and doesn't come back out. Everyone assumes he's dead, but later, Dan, very much alive, appears at Grace's and tells her he faked his death because he needs to disappear for awhile, but he'll be back to see her.