Last week's episode of 'The Killing' introduced a new suspect: Alexi Giffords, the orphaned son of the man Stan Larsen killed to escape the Polish mob. "Ghosts of the Past" is a markedly far better episode than those in recent weeks, providing plot advancement and genuine intrigue.

This week's episode is about the ways in which things haunt our characters. Richmond is coping with his new life of paralysis and Jamie believes he can prove that the mayor set Richmond up to look guilty of killing Rosie. As we saw in a previous episode, Jamie is definitely onto something. Richmond dreams of Belko shooting him again, and it's the first in a line of ghosts that come back to haunt our characters this week.

Mitch and Terry's parents pop in for a visit and suggest that people might be getting the wrong idea about Terry living with Stan while Mitch is away. And they're right. By episode's end, Stan and Terry share a kiss and a loving embrace, which is about as eye-rolling as the episode gets this week.

Speaking of Mitch, she's still off on her soul-searching journey. She finally talks to the girl at the hotel who looks like Rosie, and it's another nice way in which the title of the episode bears meaning. Mitch is haunted by the ghost of her daughter and her former life, and this young runaway is a way she believes she can help begin to repair some of that damage, and maybe understand who Rosie was.

Linden and Holder go to see Alexi's mom, who's been hiding her son from the cops. Linden appeals to her maternal instincts and gets her to give Alexi up, resulting in an eight hour-long interrogation where Linden and Holder take turns doing the good cop/bad cop routine before Alexi can lawyer up. Linden's new boss (Mark Moses, who played Duck Phillips on 'Mad Men') warns Linden that they need to play by the books now more than ever, thanks to the forged toll booth photo and the veritable crap-storm Linden and Holder unleashed on the department.

The tech department uncovers a voice mail message that Rosie left on Alexi's phone. On it, she sounds scared and mentions a man that she keeps seeing. Once again, the title "Ghosts of the Past" comes into play with this haunting audio. It's the first we've heard of Rosie in some time, and it's a much needed plot development in that it reminds us that Rosie is still the focus of this show and while she mostly serves as a subjective plot device, she was once tangible and real.

Unfortunately, just as Alexi is about to crack, his lawyer shows up and whisks him away to Janek to make sure he keeps his mouth shut. Later that evening he sneaks out to see Linden and tells her that he was trying to learn Stan's routine so he could kill him and avenge his father's death, but he fell for Rosie and the two became close. She was afraid of a black town car, similar to the one Mitch watches the young runaway girl climb into and the one Terry enters at the end of the episode. More importantly, Rosie found out the truth about her father, Stan: He wasn't her real father.

Stan finally decides to head to the police and do something he should have done long ago: sell out Janek and his mob. Stan thinks they know more about Rosie's death than they're letting on, and they're using it to manipulate him and keep him in check. Risking self-immolation for the pursuit of justice is the most noble we've seen Stan in some time.

"Ghosts of the Past" does basic, but compelling work showing us the ways in which everyone is still haunted by their past -- both distant and recent -- but it also shows us the ways in which ghosts that go even further back are still present. While Stan not being Rosie's legitimate father is certainly a striking new development, I'm not sure what bearing it has on the plot as a whole -- and that's a good thing. 'The Killing' hasn't been as involving or surprising so far this season, but bringing Alexi into the fold has provided new movement that doesn't quite gel with the formula we've gotten accustomed to. It's good to see Veena Sud and Co. shake things up without going overboard, either, and finding a way to keep Stan relevant when lately he's felt redundant and banal.