My opponent plays Wrath of God. In response I use Chord of Calling to get Selfless Spirit, so I can sacrifice Selfless Spirit and have all of my creatures become indestructible. Then my opponent responds to that action with Unsummon.
Would the Selfless Spirit's ability still resolves before the Wrath of God (and would it be sacrificed) - or - will Selfless return to my hand (and its ability will not resolve)?