Defeat the Guardian of the Falcon, obtain the Essence of the Falcon. Use Arthorn's Sparrowhawk Whistle to call Arthorn's Sparrowhawk to relay news of your success.

If you lose Arthorn's Sparrowhawk Whistle, return to Arthorn Windsong at the Evergrove for a replacement.

Chain

Morthis Whisperwing → The Ward of Wakening → Waking the Sleeper → No Mere Dream → Return to Morthis Whisperwing → To the Evergrove → The Book of the Raven → Eyes in the Sky → To Catch A Sparrowhawk → The Raven Stones → The Eagle's Essence → The Falcon's Essence → The Hawk's Essence → Return to Cenarion Refuge → Chasing the Moonstone → Vanquish the Raven God