Sometimes, it happens this way: You have scheduled four solid but terribly depressing films back-to-back. In the last twelve hours I endured — as a spectator– parental grief, institutionalized human trafficking, a marriage dissolution and, the capper, a Holocaust story.

The excellent “Rabbit Hole” is easily Nicole Kidman’s best movie since “The Hours”. Eight months after their only child’s death, Becca and Howie Corbett (Kidman and Aaron Eckhart) are having problems coping. While Howie has found some solace in a supporting group, Becca would have none of it. Her survival mechanism consists of walling up and attempting to erase the existence of her son. Her strategy is bound to collapse, but is Howie’s that much better?

The most interesting aspect of Rabbit Hole is that the entire film is about grief. Furthermore, the movie believes that pain and how we deal with it is a private matter. Rabbit Hole has little patience for religion or people with the best intentions who are perceived as intruders.

The film is directed by — of all people — by John Cameron Mitchell, whose previous efforts (Hedwig and the Angry Inch, Shortbus) didn’t quite indicate he had the light touch displayed in Rabbit Hole.

It’s also a wonderful showcase for Kidman and Eckhart. One of their blow-outs is so uncomfortable, you feel like you’re prying.

Four mournful prairie dogs (out of five).

Despite being blunt and unnecessarily obvious, The Whistleblower is likely to shake your faith in the United Nations (if you had any). An American police officer (Rachel Weisz) accepts a job as a member of the Peace Corps in Bosnia. Her job is to oversee the work of local policemen in the field.

She doesn’t have to dig very hard to find that women are second-class citizens in the area, including the justice system. But when she comes across a ring of human traffickers who force young girls into prostitution, the already appalling disparity gets so much worse.

Up to here, The Whistleblower is a fairly average exposé. Then comes the bomb. It seems most of the johns were the Peace Corps soldiers themselves. As their superiors turned a blind eye, some elements of the force even helped to get the girls through the border by smuggling them in UN trucks. Instead of adopting a full-disclosure policy, the United Nations attempted a cover-up, with the policewoman as the scapegoat.

The story packs some serious punch, enough to overcome a large list of clichés.

The Whistleblower was inspired by true events in the late ’90s. Even though many of the people implicated in the scandal have resigned, nobody has ever been prosecuted for their involvement.

Three disenchanted prairie dogs and one disgusted reviewer.

The smallest in scale of the bunch is Blue Valentine. Cindy and Dean’s marriage is on the verge. She is thoroughly disappointed with her nearly-deadbeat husband, while he can’t understand why being a good family man is not enough. Cut to six years before: A much kinder and gentler Dean wins Cindy over through song and other romantic gestures. The back and forth reveals why they fell for each other, but makes clear neither of them have the emotional maturity or a set of tools to face the pitfalls of marriage life.

Blue Valentine is at its core skeptical about the nature of love and grim in its view of marriage. This relentless pessimism is ultimately the film’s main flaw: It lacks a grey area. Superb performances by Ryan Gosling and Michelle Williams as the couple at odds.

Three and a half prairie dogs singing “All You Need is Love”.

Last stop in my cinematic descent into emotional turnmoil is Sarah’s Key. The Holocaust drama, starring the always excellent Kristin Scott-Thomas, focuses in the little known concentration camp of Vel d’Hiv, operated by the French (think the New Orleans superdome situation after Katrina, multiplied by a thousand). Scott-Thomas is a journalist looking into what happened to a Jewish family who owned in the apartment she is moving into.

Her investigation leads her to Sarah Starzynski, a young girl who in 1942 locked her little brother in the closet to save him from being arrested and sent to Vel d’Hiv, with the rest of the family. Sarah must extreme her resources in order to escape the camp and rescue the tyke from a potentially horrifying death.

The set-up is as strong as it gets, and without giving much away, the outcome of Sarah’s journey is only half of the movie. The remaining half, mainly focused in Kristin Scott-Thomas’ character, is less interesting and comes completely undone at the end. But Sarah’s Key’s main dramatic knot is totally worth your time, as a lecture about how easy is to become an accomplice in crimes against humanity.

Five Prairie Dogs for the first half, three for the second.

Tomorrow: Aronofsky’s Black Swan and hanging out with Alex de la Iglesia (Perdita Durango).