Four children set sail to a fantasy journey across the ocean. Captain Marty, logbook scribe Čen, cartoonist and cook Titánia and ship boy Kambala live through tens of adventurous events and they do not mind at all that they are not leaving their old shed at a garden in Jaroměř.

The Naive Theatre Liberec has prepared a stage adaptation of a cult book for children from 1966 (The Most Beautiful Book of 1965) which was written by Ladislav Dvorský and illustrated by Jan Schmid.. He is the founder of the legendary Studio Ypsilon and thanks to A Secret Logbook is returning after years to the Naive Theatre where he started his theatre career.