It is important to pay attention to the title of a play, especially in the case of Leslye Headland’s well-crafted “Cult of Love” currently running at the Helen Hayes. The Dahl nuclear family cult began early in the lives of the Dahl children. Diana (Shailene Woodley), Evie (Rebecca Henderson), Johnny (Christopher Sears), and Mark (Zachary Quinto) experienced a sheltered childhood with their conservative Christian parents, matriarch Ginny Dahl (Mare Cunningham) and patriarch Bill Dahl (David Rasche).

The Dahl children went to church faithfully with their parents, always “vacationed” in the Big Medows Lodge at the Shenandoah National Park and never slept over at friends’ houses (Ginny was afraid they’d be molested). They learned to play a variety of musical instruments with proficiency and were coached rigorously to sing “Oh Shenandoah” in tight four-part harmony by their father Bill.

The play takes place in the present on the first floor of the Dahl farmhouse in Connecticut on Christmas Eve when Mark is in his early forties, and his three sisters are in their mid-thirties, and Bill and Ginny are both sixty-five. The script describes the farmhouse as a place literally stuffed to the brim with goodies, evergreens and cheer. It’s an oppressive display of festivities and middle-class wealth that pushes the limits of taste.” The ideal place for a cult.

At Ginny’s dogged insistence, they have spent every Christmas Eve at the farmhouse since childhood. On this night, Mark arrives with his wife Rachel (Molly Bernard), Diana Dahl Bennett arrives with her Episcopal priest husband James Bennett (Christopher Lowell) and their new baby, Evie arrives with her pregnant wife Pippa (Roberta Colindrez), and Johnny arrives late, as he always does, with his friend Loren (Barbie Ferrara) who has been off drugs for “a hundred and twenty-six days.” Johnny is her sponsor.

It becomes clear immediately that this is not the Dahl “quintet” of the past. Although the play begins with a rousing rendition of “When Joseph The family sings in unison, in duets, and in solos. They play a variety of instruments grabbed from various locations in the room which Bill pounds away at the piano. There is another round of merriment when Johnny arrives with Loren. The full extended family spontaneously breaks out in a call and response “Children go where I send Thee.” Between singing and playing and dancing, the fissures in the fabric of the Dahl family begin to appear.

No longer a loving “Christian” family but a cult of love that has slowly fallen down a rabbit hole of delusional dysfunction and homophobia, driven partly by the mental illness that has been disregarded for far too many years. The love in the Dahl household has not been both unconditional and non-judgmental.  Ginny’s love comes with conditions, while Bill’s love has no conditions. One of those “loves” without the other does not result in true love. And no one can break free from the dysfunctional family matrix.

There is bickering about who sleeps where and who gets replaced by another sibling. Johnny does not arrive until half the evening is over. And nothing can start until Johnny arrives. There are at least two meltdowns. The “prophet” Diana completely loses her ego strength in a prolonged nervous breakdown while beating her baby bump. The siblings are concerned about Bill but have a difficult time finding the opportunity for a family meeting. Diana hurls homophobic slurs at Eva and Pippa and confronts Laura about her lack of faith and claims Laura’s addiction is a direct result of that denial of the existence of God. And Ginny blurts out “Bill can’t remember anything. He has Alzheimer’s.” One wonders why this family continues to gather yearly in such a toxic and harmful environment. Cults are difficult to escape from, especially ones that professes to nothing but love. What does hold the family together is the “harmony” achieved when singing and playing instruments.

On this night, however, even that is not enough. Eva and Pippa leave for the hotel where they are staying and promise not to come back the next morning for the family photo. Rachel leaves with Loren – both heading back home. Eva and Pippa do return for the photo, but it is clear (or is it?) that a tipping point might have been reached, and this will be the last Dahl Christmas Eve reunion. As the lights fade, that is the only hope that remains for this damaged and damaging extended family.

Trip Cullum directs with the prevenient grace that allows the superb cast to surgically peel back the layers and layers of dysfunction that playwright Leslye Headland has constructed in this not to be missed play.