Based on the novel of the same name by Yurii Mushketyk. For the second year, a laboratory headed by professor Marchenko has been working on the problem of photosynthesis. The work absorbs the entire team – each new result seems to confirm the correctness of the leader’s theory. The scientist Borozna, convinced that his colleague’s research path is mistaken, makes it clear to a doctor that it is time to stop and take a more critical look at the results.
| Actor | Role |
|---|---|
| YYevhen LysenkoDmytro Marchenko | Dmytro Marchenko |
 Vsevolod ShilovskyVizyr | Vizyr |
| IIrina TereshenkovaIryna Mykhailivna | Iryna Mykhailivna |
 Aleksandra TurganNelia | Nelia |
 Vladimir TyukinViktor Borozna | Viktor Borozna |
 Leonid YanovskyiHolovko | Holovko |
 Zdislav StommaKoretskyi | Koretskyi |
 Iryna BuninaLipekha | Lipekha |
 Liudmyla LobzaKhorol | Khorol |
| VVyacheslav SlankoBabenko | Babenko |
 Ihor ShkurynYulii | Yulii |
| PP. KysliakNot listed | Not listed |
 Bohdan ZholdakNot listed | Not listed |
| MMiroslav ZalevskyNot listed | Not listed |
 Lyudmila KuzminaNot listed | Not listed |
 Galina KalashnikovaNot listed | Not listed |
| MM. YevtushokNot listed | Not listed |
 Oksana HryhorovychNot listed | Not listed |