During the time of the Byzantine Empire, two young men, Asotis Taronitis and Alexios Argyras, are captured when the Bulgarian army seizes Thessaloniki.

The daughter of the Bulgarian king Samuel falls in love with Asotis, and the king frees the two young men, offering them positions of power and high ranks.

When the Bulgarian king attacks Byzantium again, the two friends abandon their privileges and return to their homeland, where Alexios is betrothed to Thekla.

The war between the two countries continues, and Alexios undertakes a dangerous mission entrusted to him by the emperor.

Thekla disguises herself as a boy and follows her beloved. The young couple, in their attempt to carry out the mission, will become involved in dramatic adventures and face deadly dangers.

The only weapons of the young couple are self-sacrifice and faith in higher ideals that transcend personal interest.