Sure Fire is the first in the four-book series written by Jack Higgins, and co-written by Justin Richards. This is when we first meet the Chance Twins, Jade and Rich. Several other characters are also involved.
The story begins with the revelation that Jade and Rich's mother is dead. She died in a car crash, leaving Jade and Rich alone, as they do not have a father. However, at the funeral service, a man arrives, and claims he is their father. He claims his name is John Chance.
When Jade and Rich move in to their dad's flat, they are puzzled by his secrecy. For example, he has an encrypted phone, with a special box that means no-one can listen in on calls. Jade, who is a health freak, isn't happy to find out he smokes, and that his fridge is full of beer.
When sneaking into their father's study, they discover he is planning to send them off to boarding school - but there are two lists - one for girls, and one for boys. He is going to split them up. They confront 'dad' about this, and he explains that there were no boarding schools with two spaces in the same year, so that was the best he can do. Jade and Rich believe he just wants to get rid of them.
One night, they overhear dad making a phone call, and realise he is planning to meet someone at a dump yard. They decide to tail him, and work out his reason for secrecy. However, unknown to them, they ruin dad's plans. By following him, they are a lead for unknown enemies, as well as a way to get to John Chance.
When they lose him in a set of alleys, they go to a book shop and use an A-Z of London to find where he's heading. All the time, the enemy follows them.
They are in time to see Dad enter the dump yard, and they follow him in. Then they watch in the shadows, to see who he is meeting. However, Dad is ambushed, due to the fact the enemy followed Jade and Rich. Though he knocks many of them unconscious, he is outnumbered, and they have guns, and he eventually surrenders. Just before he is taken away, he sees Jade and Rich in the shadows.