Fatale Mutterliebe (1995)

After separating from her husband Werner, who now has a new wife, Paula lives alone with her young son Philipp. After the little boy runs away from home, the ex and his new wife try everything to take advantage of the situation. It doesn't all seem to be right either, because shortly afterwards there is a fire in Paula and Philipp's apartment - and it looks as if someone set the fire on purpose.