A storm. A ship on the rocks. The light is dead —
and the two of you are in different rooms.
The lamp has gone dark in the worst of it, and there's a ship out past the rocks with no way to find the channel. Without this light she'll never find her way in.
The old keeper rigged this light with his own locks and split every secret in two — he never trusted one person with the whole of anything. So you've split up: one up in the lamp room, one below in the keeper's quarters. You each see different things.
Every lock needs both halves. Read what you find out loud, listen to what your partner found, and put the two together. Neither of you can light this beacon alone.