Patrick Jane's obsession with Red John stems from a wound created by Red John's murder of Jane's wife and child.
In Thursday's episode (10/9c on CBS), fresh salt gets poured in that wound when Jane (Simon Baker) has a run-in with his con-man brother-in-law. Danny Ruskin, (guest star Kevin Rankin), who still blames Jane for his sister's death.
The Mentalist: Has Jane lost Red John's cat-and-mouse game?
"The resentment is still fresh," Rankin tells TVGuide.com, noting that his character isn't just angry with Jane because of his sister's murder. "Danny was sort of the wonder boy of his family and a mini version of Patrick Jane. When Patrick came into his life and married his sister, he really stole his thunder. There was a bit of jealousy and envy. But he did respect him."
It's perhaps that respect that forces Danny to call on Jane for help when Danny becomes a murder suspect. That, and the chance to match wits with Jane once more.
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"He's smart enough to know he can't just pick up the phone and call Patrick up. So I con him into helping me," Rankin says. "There's still a bit of tit for tat going on between us. ...Viewers should really pay attention to the wordplay between Patrick and Danny. You're going to see the most honest Patrick Jane you've seen thus far."
Rankin says that honesty comes from Jane's acceptance of all the blame Danny dishes out. "Danny's laying into him, and Jane's just taking it and being fully open," Rankin says. "We're going to see a little resolution, not only for my character, but for Patrick because Danny is a representative of Jane's lost family. Jane feels guilty, and he takes it like a man because he does feel responsible."
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Series creator Bruno Heller says Jane's responsibility forces him to take on Danny's case, despite the bad blood. "Jane is sort of morally obliged to treat him well because he's the last living connection to everything Jane held dear," Heller says. "It's the first time we've seen him with genuine family, and the love he had for his wife is sort of transferred to [her] ne'er-do-well brother."
Rankin says his character's story ends with the possibility for his character to return in the future. But regardless of where Danny goes, Rankin suspects viewers will see a changed and perhaps reinvigorated Jane.
"I think him dealing with Danny is the best thing to happen to him in awhile to because it's as if he's getting to communicate with the dead in a way," Rankin says. "He is at least some sort of closure. Even though he can't get the ultimate closure by getting Red John, I think he carries from this a little more peace. But Danny also could've woken a ferocious demon."