Is Volley Spell a free or immediate action?

[sk8r_dan_man]

Volley Spell (Su): At 15th level, when a targeted spell or spell-like ability fails to overcome a flowing monk's spell resistance, he may reflect the effect onto its caster as spell turning by spending a number of points from his ki pool equal to 1/2 the spell's level (minimum 1).

It doesn't say if this is a free or immediate action. I'd like to assume it's a free action, but most other ki powered abilities are swift actions, so I'm not sure.

[FLite]

By definition it would have to happen during someone else's turn, so immediate action is the only one it can be.

[Morgen]

It appears that it isn't any kind of action at all. Simply something extra that gets added onto their spell resistance. If it were an immediate action it would explicitly say so.

[DM_Blake]

No action.

Neither Spell Turning nor Spell Volley specifies any action at all. Spell Turning is automatic, the caster does not even need to spend Ki points or anything else to use Spell Turning, it just happens, automatically, when he is the target of a spell.

Spell Volley says it works just like Spell Turning (except for the Ki points) and since it doesn't list any other exception (such as describing an immediate action or any other kind of action), then we must default to the way Spell Turning works - no action required.

However, I would not be surprised to see an errata some day saying that it should be an Immediate action, just like all the other out-of-turn Ki abilities the Flowing Monk has.