According to Norse myth, Baldur, son of Odin and Frigg, was a god of truth and light,

and he began having disturbing visions of his own tragic death.

So Frigg set out to command every plant, every animal, and every inanimate object in the universe

to swear an oath, never to harm Beldor.

And the plan appeared to work.

It worked so well that the other gods would make a game of it during a celebration that was held

in honor of Bauder's new invincibility.

If nothing in the universe could kill Balder, then you could throw literally

anything in his way and he'd walk away unscathed. And so they did. And that caught the attention

of Loki, a god known for playing tricks and generally upsetting the status quo. He was able to find

out that Frigg had actually neglected to ask one thing to swear an oath of no harm to Balder.

It was the small and harmless plant that usually was found growing off of other trees.

With its tapered oblong leaves and its small white berries, Frigg had assumed that it was harmless to begin with,

and so there was no need to solicit an oath.

Loki went to the forest and found some of the plant and tore off a branch, and then he returned to

the party. And there he tricked Baldur's brother to throw the branch at Balder. The branch

pierced Baldur's heart, and he died. And that plant was mistletoe.

So why would mistletoe play such an important role in a story like that?

And how do we get from an ancient myth about it killing a god

to a modern custom of kissing beneath it at Christmas time?

It's a story of superstitious ancestors,

fertility rituals, the Protestant Reformation, and birds do in their business.

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