For many people, the most important purpose is to plan to achieve certain definite objectives, using the shared imagery, sexuality and sensuality as a focus. Well, now you have all the tools, if you so wish (remember that the "secret" could be put onto an advertising hoarding, and only those who understand would even notice). Unless you're experienced or just browsing, you'll probably be better off developing your own imagery before reading what follows, but consider:
The knight is making a familiar journey. The path is well defined and easily visible even in the gathering darkness of the evening. The last rays of the setting sun have just left the tops of the trees in the distance, the sky almost green as the light fades. He knows the way, bare feet across soft grass, the hem of a simple robe catching the dew, the scent of the night flowers becoming subtly stronger. Still, there is, as always, a faint apprehension, a slight tightening of the belly. Soundlessly, but with resolution, he moves on.
The well is surrounded by trees, which provide a low background sound, almost musical. The setting isn't in the slightest claustrophobic - the fallen leaves on the surface of the water make dark patches against the scant reflected light of the night sky. She sits on the warm flagstones that surround the pool, joyful in the darkness, waiting. She is naked beneath a shift that provides just sufficient warmth and no more, her body thrilling to the night air.
He has brought flints and a tallow candle, which he lights and sets at the far end of the pool. It gutters at first, then takes hold and throws long shadows against the curtain of the trees. He presents her with a handful of lily petals. She throws them into the water, white specks amongst the dark leaves. The space surrounding them seems to contract, the comforting trees a latticework of green.
The mortals know there is nothing to fear, but knowing and feeling are two different things. Still, they trust each other, and have learned the secrets of the ancient ways together in times of old. They are simply taking up once more what they set aside so long ago - only a single instant has passed. He has in mind a simple act of worship, holding the image, seeking no favours, merely... completeness. Since he asks nothing, she will grant his every desire. This night, whatever they wish... can be. But, from ages past, they know better than to ask too much.
Rising, she shucks her white shift to stand naked and proud before him. He follows her lead, folding his heavier cloak carefully with hers. She pours black wine into the chalice, first holding it for him to drink, then drinking from it in turn as he holds it. They drink greedily, wine splashing breasts and bellies. Finally, on the cusp between worlds, they simply hold hands and stare into each other's eyes for a moment, then embrace.
The knight and the maiden are gone. Robed in ritual, the Lord and Lady are fully present. Consorts of old, they take joy in each other, gently igniting the ancient fires. Within the embrace of the trees, he reaches down into the water, drawing a cupped handful with which to anoint his lover. The water ripples, the highlights reflecting something rather more than the deep blue of the sky. The Lady revels equally in his touch and in the cool water. Her consort can deny her nothing. He lifts her gently and the candlelight catches her hair as he lays her reverently on the warm, dry flags.
Comfortable together, they embrace. There is all the time in the world - indeed, there is all of the world. Slowly, gently, passions build within them, he lost in worship, she gently guiding, wrapped in warmth, in love and rapture.
The universe contracts. Time and space cease and there is only the well in the trees, the Lord and Lady together, pleasure surrounding them, comforting them and empowering them, for pleasure is their ritual. The Lord is completed within the Lady, held fast within her beauty, giving fully of himself and asking nothing. She gives and accepts freely, delighting in his pleasure, a chalice of transforming joy.
Gentle light suffuses the world. The white petals and dark leaves are still floating on the gentle ripples of the pool, almost motionless as water moves beneath them. The world is beautiful, joyfully expanding to encompass petals, leaves and water alike, soft waves that never break. The light deepens, thickens around the Lord and Lady as if they, too, were floating, bliss moving gently beneath them, never ending.
Gradually, pleasure fills the contracted universe: the Graal is not in the world. Holding fast the images of joy, of the quest and of the ancient wisdom, the two spirits fully merge in the well-tried mystery as they approach the crest. And finally, the world of pleasure and ritual expands and the whole universe is within their realm.
In that moment, which will last forever, all is possible.
At last, she stands, and a single pearl falls rippling into the water. There was indeed nothing to fear. Once more mortal, they embrace, revelling in the slight chill of the late evening. The knight wraps them together in his cloak, and snuffs the candle. Wrapped together in moonlight and more, they kiss, fully content.
Who knows where the path will lead? The journey is as important as the destination. As in Tolkien's poem, the road goes ever on.