Alacrity

You become capable of bursts of reality-defying quickness. Your speed is doubled, your movement and actions don't trigger reactions from hostile creatures, and you can take one reaction on every turn in combat.

Also, you can move through objects and the spaces of other creatures. Doing so doesn't count as difficult terrain. If you end your turn in an object or another creature's space, you are shunted to the last unoccupied space you occupied, and you take 1d8 force damage.