When dropping his teenage daughter off at her ex's lavish property, Dino (Bentivoglio) falls in love with the expansive grounds, the swimming pool, the tennis court and the detached coolness of its owner, businessman Giovanni (Gifuni). Dino sacrifices his business, putting his house up as collateral, to pull together the cash for one of Giovanni's investment opportunities. Meanwhile, ignored by her distracted and aloof husband, Giovanni's trophy wife Carla (Bruni Tedeschi) looks to open a theatre in the city and contemplates an affair, while Dino's daughter Serena (Gioli) flirts with a local boy with a troubled past.
These stories entwine, overlap and double back on each other as Virzi's adaptation of Stephen Amidom's novel works its way up to the answer to the question asked in the opening sequence: which one of these characters knocked down the cyclist in a hit-and-run incident on a dark country road? Each story has a different perspective on the accident and each character has a reason to cover it up, with Virzi delighting in throwing up red herrings.
In the rush around, however, the story forgets about the cyclist as it explores the lives of those concerned, and their stories succumb to some convenient coincidences. If only the characters were interesting but Gifuni's businessman is your typical richie with the expected air of entitlement, Bentivoglio's social climber is just spineless, and it's too difficult to care what Matilde Gioli is up to.
What keeps things afloat is Valeria Bruni Tedeschi. Displaying a quiet desperation and sadness while struggling hard to keep polite and smiling, as a woman of her standing is supposed to, Bruni Tedeschi is magical. At one point she manages to squeeze all this inner turmoil into a question about biscuits. It's her story that engages the most, the only one that could possibly be expanded to a full feature. Bruni Tedeschi is perfect and there isn't nearly enough of her.
Human Capital might keep one guessing with regards to the Whodunnit and there is a real momentum, and a creeping dread, to the proceedings but bar Bruni Tedeschi's middle-aged depressed trophy wife the characters are too bland to involve.