Pouring out a libation of mingled blood and wine upon the imaginary skull of Robert Graves, one might receive the following oracle:

Ravenscroft is an example of iconotropy, i. e., the misinterpretation of religious imagery when the image has outlived the cult which inspired it. In this case, in a series of rituals enacted annually:
1) the hero impregnates the priestess of the reindeer cult
2) the hero is sacrificed to the reindeer spirit
3) wolves and ravens accept the offering on behalf of the reindeer spirit
4) the spirit of the hero is saved by the reindeer-priestess

Some Scandinavian reindeer cultist inscribed these scenes on pottery where centuries later they were seen by a British bard and made into a song. The reindeer become fallow deer, because the bard has never seen reindeer, but the antlers in the picture remind him of those of fallow deer, both having flat blades instead of the tines characteristic of most other species of deer. The sacred victim becomes an ambushed knight. The ravens and wolves gathering to devour the offering become hawks and hounds protecting the corpse; except where the ravens, recognisable as such because they are shown actively devouring the victim, are cast as opportunistic scavengers rather than as embodiments of the reindeer spirit. The victim's spirit is reincarnated in the priestess's unborn child, as is shown in an image of a pregnant woman in reindeer costume carrying the victim; but the bard sees this as a scene of a magically transformed bereaved woman ministering to her lover's remains. (If the priestess's baby is a girl, she becomes a reindeer priestess too; if a boy, he's a future victim.) As for the earthen lake, perhaps it's a peat bog, where neolithic northerners habitually deposited the remains of sacrificed humans.