。
Shall we go home?
Literal
Home [target-に] return [volitional-ましょう-question-か]?
~ましょうか is the polite volitional form used to make a suggestion or offer: 'shall we X?' or 'shall I X?' The か marks it as a question, softening the volitional from a declaration ('let's X') into a proposal. Adding か also opens the possibility of the listener declining.