After training at the dolphin reconnaissance school, the dolphin Tristan was sent on an important mission to a secret military base of the USSR to obtain information about the Russians' new strategic weapon - a submarine that transforms into an airplane. After receiving a message that an unidentified object was discovered in Soviet territorial waters, moving towards a secret base, the Soviet command ordered to urgently send an experienced special agent, the dolphin Isolde, to intercept it.
| Directing | Vladimir Tarasov | Director |
| Directing | Rasa Strautmane | Director |
| Directing | Aleksandr Mazaev | Director |
| Writing | Eduard Uspensky | Writer |
| Camera | Kabul Rasulov | Director of Photography |
| Camera | Aleksandr Chekhovskiy | Director of Photography |
| Sound | Eduard Artemyev | Music |
| Directing | Aleksandr Gorlenko | Director |
| Directing | Elena Prorokova | Director |
| Camera | Nataliya Mikhaylova | Camera Operator |
| Art | Natalia Demidova | Production Design |
| Art | Yuriy Batanin | Production Design |