Complex sentence: The prodigal Zhenya is constantly running off on his own for days, sometimes in the company of street children, in the depths of the Moscow winter-and Arkady senses things are starting to sour between him and Dr. Eva Kazko.
Split into simpler sentences: The prodigal Zhenya is constantly running off on his own for days, sometimes in the company of street children, in the depths of the Moscow winter. Arkady also senses things are starting to sour between him and Dr. Eva Kazko.