Mission Dilettante. Lie without an expiration date

According to the new methodology developed by the brilliant professor of psychology, four unfamiliar people are taken to each other to the amateur group. One by one, they are simple average people without special talents - a student, an ITSHAN, a pedicure and Mamenkin’s son of noble blood, but, having formed a team, turn into real detectives that can reveal even the most confusing deeds. A year ago from a private collection. Moreover, the owner is sure that the canvas is still in the house.
Will the amateurs do the task? After all, the matter is complicated by the fact that the professor died, absolutely all the inhabitants of this strange house are lying, and a secret also pops up, which was carefully hidden from outsiders for more than a dozen years