The locking mechanism in our kitchen door is properly broken. (It's a sliding French door - probably about 20 years old). We had to call emergency locksmiths out tonight who said it's be cheaper to replace the door than the mechanism.
DH didn't like the cut of their jib / wasn't overwhelmed with their expertise so isn't sure,
In the meantime we got them to screw it closed to make sure the house is secure (plenty of other close exits in case of fire). It was 11pm by this time and I wasn't going to bed with an unlocked door.