If you cast Retreat on a unit, hold focus, then cast another Retreat targeting the same unit, what happens when both Retreats resolve?

Ruling: Targeting happens when the spell is put on the chain and cannot be changed. The first Retreat to resolve (cast second) will return the unit to hand. The second Retreat to resolve (cast first) will still resolve but whiff - it cannot return the target because it's already gone, and it cannot establish "its owner" because the unit is off the board and returns a null value.

Sequence:

• Both Retreats are cast targeting the same unit (targeting locked when cast)
• Second Retreat cast resolves first, returning the unit to hand
• First Retreat cast resolves second but whiffs (cannot return already-gone unit)

Nuances:

• The whiffed Retreat still resolves, it just fails to do anything because its target is no longer on the board
• The off-board unit returns a null value for "its owner" so that part of the effect also fails