The copy with the fifth cover was printed in a limited print run and will not be resupplied.
Tesco.com who are selling the fifth cover are also offering the opportunity to purchase all 5 covers in one shrink wrap set. This comes with 5 postcards (based on the 5 covers) in an envelope. There are only 100 of these sets, so they are also considered a limited edition.
In terms of the competition, this is to win a signed, leather bound hardback edition of Under the Dome. This is a complete one off, and will not be reproduced for any other customer / retailer in the future. In other words, there is one (1) copy of this book!
The contest is open to anyone, anywhere (except Hodder & Stoughton employees and their families) so enter now!
You can enter the contest here.