Bifrost is the rainbow bridge that connects Asgard, the home of the Norse gods, to Midgard, the world of men.
Our poster shows Odin riding his eight legged horse Sleipnir down the Bifrost from Asgard to Midgard - represented here by the Midgard serpent, Jormungander. Both Sleipnir and Jormungander are children of the trickster god Loki. Jormungander by the giantess Angrboda, and Sleipnir with the stallion Svadilfari.
The runes are written in old norse, and translate to: Allfather, not some father.