Treacherous Tower

You walk down a long stone passage, you don't how long you have been walking for - it may be days or even weeks. Your way is lit by Japanese lanterns hanging from the walls. Finally you take a sharp turn left and find yourself in the remains of a kitchen. There are rotten old pots and pans lying around all over the floor.

On the counter there is a loaf of bread with ham and cheese inside it, and a large jug of water, with a note pinned onto a pinboard beside the food and drink. The note says:

Dear friend,

I have left these two things that you may choose from. You may choose only one of them, and only one of them will prove useful to you (the other one will not harm you, I can tell you that).

Pick one, and run down the left passage which you have not yet explored.

From your friend, the owner of Treacherous Tower.