The witness should have given you important documents. He is afraid of persecution and set you up in the garden. When you came, nobody turned up, you wandered around a bit and decided to leave, but the gate, which had been open before, was now locked. This is a trap, the garden belongs to a private person and, if you are found here, there will be trouble. It is necessary to get out urgently, but there is a difficult lock on the gate, but with a code. The solution is hidden in the garden, try to find it and do it as soon as possible in the Garden Gate Escape.
