This series is centred on Raquel and Viruca, two literature teachers working in a small Spanish town. Raquel moves to the town with her husband, who is a local, to take up the teaching position. She didn't know that her predecessor, Viruca, had died in a presumed suicide. The more she learns the more Raquel starts to think Virura may have been murdered, possibly by somebody in her class. As the series progresses we see Raquel's story intertwined with flashbacks of the events leading to Viruca's death.
This is a somewhat mixed series; on the down side one does have to suspend one's disbelief at times... watching the series one would think there was only one class at the school and the way the students and teachers interact seems highly unlikely; it is far too casual and students get away with threatening teachers. If you can get passed those problems the central mystery is gripping and there were plenty of genuinely tense moments. As the series progresses more suspects emerge as we learn about various activities going on in the town which include affairs, sexual jealousy, shady financial dealings and drugs. The cast is solid; most noticeably Inma Cuesta and Bárbara Lennie as Raquel and Viruca. Overall I'd recommend this despite its problems; if you want a good mystery it is definitely worth watching.
These comments are based on watching the Series in Spanish with English subtitles.