Quick Answer
Walk up from the beach with your partner, cross the plain, go through the cave to the hall, and both hold one handle of the double door at the same time. There is no puzzle on The Shoreline, Chapter 1 of We Were Here Tomorrow: the only thing that stops you is that door, and it needs both players holding on together.
How Do You Get Through The Shoreline?
Walk up from the beach with your partner, cross the plain, go through the cave to the hall, and hold the two handles of the double door at the same time. The Shoreline is Chapter 1, and its only checkpoint is The Search.
Leave the beach together
You start on the beach with your partner, and there is no way back into the water, so head up the slope. Some of the climb is a scramble over rocks; as one player put it on stream, "We had to finagle our way up."
This is a good moment to find the emote wheel. It is on the T key on keyboard, and you will use it later in the game.
Follow the credits across the plain
Keep walking inland across the snowy plain. The opening credits appear along the route, written across the rocks, which is how you know you are going the right way.
The opening credits float over the snowy rocks as you cross the plain.
Shown at 06:45 in Grillmastah’s video.The credits catch most players off guard. "Oh, that's that's a credit sequence," one streamer said, and another called them out straight away: "The credits are haunted."
Go through the cave to the hall
Enter the cave at the far side of the plain and follow the passage toward the hall. A red light shows ahead in the cave; "I'm seeing a big red light," as one player called it. Keep heading toward it.
The cave passage glows red ahead of you on the way to the hall.
Shown at 07:51 in Grillmastah’s video.Hold both door handles at once
At the end of the hall is a double door with two handles. Each of you holds one handle, and you both have to hold at the same time. One player holding a handle alone does nothing.
When both handles are held together, the opening film plays and takes you to the next chapter.
There is no puzzle to solve on The Shoreline. If you are stuck, you are almost always at the double door: check that your partner is holding the other handle at the same moment.
Next, continue with the Rehabilitation Suite walkthrough at the start of Chapter 2: The R&D Headquarters.
FAQ
Walk up from the beach together, cross the snowy plain, go through the cave to the hall, and hold both handles of the double door at the same time. That plays the opening film and ends Chapter 1.
Each player holds one of the door's two handles, and you have to hold them at the same time. One player on one handle does nothing.
The Search is the only checkpoint in Chapter 1, The Shoreline. It runs from the beach to the double door at the end of the hall.