Setting Sail

Talk to Katheryne in Liyue Harbor

First things first, you need to chat with Katheryne at the Adventurer's Guild. If you've forgotten where it is, just open your map, teleport to the lower Liyue Harbor Waypoint, and head east. You'll tell her you're off to Inazuma and can't take on any more commissions for a bit. Just as you're talking, a Sea Drake will show up to let you know Captain Beidou is ready for you and waiting on her ship, the Alcor, which is anchored near Guyun Stone Forest. Katheryne might make a little joke about her being in multiple places at once, but the Sea Drake confirms the Alcor is waiting for your arrival.

Board the Alcor and find Beidou

Now, let's get to the ship! Teleport to the Domain of Guyun. From there, head east and start climbing the mountain to your right. Once you reach the top, you'll need to glide towards the Alcor. Aim for the first oar you see, and climb up it towards the rope on the ship. Keep climbing until you're aboard. Once you've made it onto the deck, head towards the southern end of the ship. You'll find Beidou waiting there, so go ahead and speak with her.

Talk to Beidou

Beidou will greet you with a bit of a joke about you being late, and then you'll get to see a cutscene. After the scene wraps up, you'll find yourself in Inazuma, where you and Beidou will be met by Thoma. Beidou will try to introduce you, but it turns out your reputation has already reached Inazuma! Thoma will explain that he's the go-to guy in Ritou and will instruct you to get registered at the border checkpoint. Once this scene is over, the quest will conclude, and the next one will start right away.