It's around

a week now since you started work on this task, and it hasn't gotten any easier. No rest
for the wicked though, and so you sit down at your desk for another day of work. Shortly
after you start, you hear a familiar knock on the door.

Click here to greet the postman.

Click here to have another look at the second message.

Click here to have another look at the first message.

To research possible leads, you can go to the MI5 secret library by adding '/library' to the URL.