Photo: Switching Souls: A young bride and a dying old man test the limits of one groom''s love.

One of the few things to expect from playwright Craig Lucas is the unexpected. Lucas'' plays are always unusual in structure or approach, whether we are meeting a motley crew of dinner guests, a wife on the run from the husband who has taken a contract out on her life, or, as in The Western Stage''s season opener Prelude to a Kiss, a young couple given the chance to find the meaning of true love. He manages to find the grace, the sweetness of life without overlooking life''s harsh realities-poverty, change, the failure of love, death.

Prelude to a Kiss is billed as "a light-hearted adult fairy tale" and it does not disappoint. Peter and Rita meet at a party: Peter is a poster boy for child neglect, yet now a young man, he has chosen to move beyond his questionable upbringing; Rita sees the misery and injustice in the world and cannot bring herself to bear children into it. After a courtship of only six weeks, they decide to marry. Sure, in their wedding vows they promise eternal love through good times and bad, till death do them part. But how much meaning do those promises carry in today''s world?

Rita and Peter are given a chance to find out in the magical world of Lucas'' play when an old man asks to be allowed to kiss the bride. When he does, Rita and the old man switch souls. Age experiences renewed youth in the body of a beautiful young woman. The frightened girl confronts mortality in the body of a dying old man. True love sees beyond the surface to the heart of the matter.

Western Stage''s production could hardly be more delightful. From the moment the audience enters the theatre, we are carried away into Lucas'' fairytale world. The scenic design by Lynne Willis is heavily influenced by African and Caribbean art. It is the definition of form following function: spectacular to look at and marvelously efficient for moving through the 21 scenes of the play. And the "magic cupboard" from which costumes and props spring as needed is an imaginative touch.

To add to the festivities, director Jeff McGrath starts out with the actors engaged in a pre-show party complete with a plastic palm tree, drinks with pink flamingo straws, and limbo. He keeps the show fast-paced and fluidly moving, the actors energetic and committed throughout.

As Peter, Joel Bischoff is terrific. He is warm and engaging, immediately likeable. Whether he is explaining his predicament to the audience or courting his Rita, we are rooting for him. Peter is the backbone of the play, and Bischoff is fully up to the job.

Heather Barberie is a wonderful match for him. Rita is a challenging role, requiring the actor to play the real Rita, then the Rita possessed by an old man. Barberie is lovely, tough yet vulnerable, and her transformation is both charmingly comic and touchingly honest.

As the old man who is turn possessed by the soul of Rita, Richard Courtney is both believable and very moving. He allows the audience to buy that Peter can see through the hirsute exterior to the fragile, beloved girl within and we can forgive him for the unarticulated passions that drove him to the accidental transformation.

An outstanding cast of supporting actors play multiple characters in the play. Longtime Western Stage favorite Pat Horsley is quirky and loveable as Rita''s mother, Eleanor Wylde is perfect as the old man''s daughter, Elizabeth Miles is a radiant presence in several roles. Denny Vierra as Rita''s dentist father is full of joie de vivre and ideally protective and overbearing. Michael Daley is very funny indeed as Peter''s co-worker and friend.

Prelude to a Kiss is a comedy that respects its audience enough to allow us to be thinking, feeling individuals. It is a comedy with a soul. What a pleasure!

Prelude to a Kiss continues at the Western Stage through June 22.