Merli Bergeron is a middle-aged philosophy professor who loses his apartment just as his ex-wife takes a job in Rome. He accepts the responsibility to raise their teenage son while moving them into his mother's apartment in Barcelona. A job opens at his son Bruno's school. Happy to be employed, he immediately disrupts the order among his colleagues and sparks discussion in his classroom, much to Bruno's chagrin. Each episode focuses on a particular philosopher and their ideas. Merli demonstrates Aristotle's Peripatetics (the act of movement to bring forth robust ideas) and inspires his class to engage one another and to express their thoughts and ideas. Written by o2bwiser

Merlí encourages his students to write poetry, and visits the home of agoraphobic student Ivan. Tània coaxes Bruno into opening up to her.

Merlí gets a visit from Gerard's mother. Bruno thinks Eugeni is grading him unfairly because he's Merlí's son. Gerard falls in love at first sight.

During an overnight study session, Pol becomes suspicious of Bruno. Eugeni accuses Bruno and Pol of cheating on a test. Joan asks Merlí about justice.

Joan's father thinks Merlí is brainwashing his son. Bruno tries to console Tània after a friend betrays her. Merlí forces Ivan to go outdoors.

Berta acts out in class. Mònica invites Gerard to her home to work on a class assignment together. Gina learns Merlí has been seeing Laia.

Pol suffers financial and personal difficulties at home. Gerard finds evidence suggesting his mother has a lover. Joan rebels against his parents.

An intimate video of Mònica circulates among the students. At the museum, Marc spots Merlí and Gina kissing. Ivan learns his mother has a boyfriend.

The students throw a wild birthday party for Pol at Mònica's house, where Joan makes a drunken confession, and two friends act on a mutual attraction.

A major conflict erupts in Joan's family. Pol distances himself from Bruno. Gerard refuses to accept his mother's relationship with Merlí.

Eugeni gets a nasty surprise. Pol is tasked with tutoring Ivan. Merlí discovers Berta's hidden talent. A new student makes a strong first impression.

Joan refuses to participate in the school food drive organized by his parents. Oliver is ridiculed and shunned by his male peers, including Bruno.

Plans to discontinue Merlí's classes incite a protest. Joan acts on his feelings for Mònica. Bruno confides in Oliver. Ivan makes a breakthrough.