Complex sentence: Moonlight and romantic music combined with an aphrodisiac spell have the Alphans on the verge of consumating their new relationships--when the mood is shattered by an unearthly howling.
Split into simpler sentences: Moonlight and romantic music--in conjunction with powerful aphrodisiac-like influence--have the Alphans on the verge of consumating their new relationships. The mood is shattered by an unearthly howling.