Literary fame beckons for Olga Pushkin, Railway Engineer (Second Class), when her self-help manual for hard-working women is published at last. In the meantime, however, Olga still has a household to support, a hedgehog to feed, and railway tracks to maintain from her tiny Siberian village of Roslazny, which has just become the target for Russian Railways budget cuts. Worse still, her beloved sergeant of police, Vassily Marushkin, has reunited with his long-lost wife Rozalina. And soon Rozalina is forcing Vassily to consider moving away...

Matters aren't helped when Olga's scheming superior, Boris Andreyev, forces her to babysit a special Romanov-themed murder mystery steam train doing the rounds of the local towns. Parked in a siding near Roslazny, the players deliver the first of several intended performances - only for a staged murder to become very real. Vassily starts a homicide investigation in conjunction with his boss, the mercurial Captain Zemsky, but both are baffled when another murder follows on the heels of the first.

Old-school Zemsky bans Olga from joining the investigation - but she soon makes vital discoveries that point towards something deeper and more worrying than the murders alone. Further afield, a rival author emerges to steal Olga's crown, while back in Roslazny Olga begins to suspect that Vassily's wife Rozalina might be hiding secrets of her own. With chaos striking Roslazny, can Olga solve the murders, save her literary career, and settle Rozalina's identity before she loses Vassily forever?