she embraced him around the neck with her arms and wrapped her thighs around his back , fluttering like a butterfly and lowering herself upright onto his rigid phallus , her lotus position entwined with his , and they made love in the yab-yum position atop the ziggurat , liquid purple flowing from her body and liquid darkness flowing from his , in yet more rivers down the pyramid , double helixes of shadow and light , growing wider and wider , swelling as though with flood , until their purple and black energy poured down the drug topiary in one continuous ocean , which was eternally returned to them by the fountains of elixir .