The target is seized with a passionate, usually sexual, interest in the caster. The force of the passion grows with each sleeping hour. Consciousness abates the increasing force of the attraction, but on returning to sleep, the spell continues its inexorable climb. The effect is triggered when the victim sees the caster next.
Bear in mind that once the peak of the spell's force has been achieved, it will start to decline in reverse order. Care must be taken with regard to the timing of this spell.
Once the force of the passion has been set, then subsequent actions may change the way the victim feels about the caster.