Equation with Three Unknowns

Lenazolotareva and her beloved husband Viktor Doroshin had not rested without children for a long time. And then a chance came up – the anniversary of Viktor's old friend, the famous antiquarian Eduard Kireev. Why not combine the pleasant with the useful? And Lena's unexpected find in the antique shop – a painting by an unknown artist that caught her attention – only added to their joy. But they could not have imagined that this was the beginning of a chain of surprises. The morning after the banquet, the anniversary celebrant was found dead. It later turns out that someone is hunting the other inhabitants of the estate as well…