2.1. Bide
From the Basic Ability List in the Appendix:
Time: *Free Action or Quick Action Target: Self
Choose an Ability that is an Action, Quick Action, or Free Action. If you choose an Action, you must spend a Beat now, treating this Ability as a Quick Action instead of a Free Action.
Next, choose a Reaction Trigger of your own making. Until your next Turn, you can use the chosen Ability as a Reaction with your chosen Reaction Trigger. The Reaction Trigger you choose should be somewhat specific and represent how your character is preparing to use the Ability, like "when a creature becomes visible," or "when a creature enters Swinging Distance(1u)" of me.
Next Up: 2.1. Move