Jason Isaacs Accidentally Injured Tom Felton With His Cane While Filming Harry Potter

Jason Isaacs and Tom Felton's Lucius and Draco Malfoy are two of the most controversial figures in the "Harry Potter" movies. While Malfoy senior is known for being a vile, malicious, and manipulative pure-blood wizard and Death Eater, Draco, on the other hand, is a bit more tragic. He started as a spoiled and self-centered bully until the burden of living with his father and being in Voldemort's orbit caught up with him.

Lucius and Draco are often seen in scenes together, with the former always towering above his son with his cane — a walking stick concealing his wand, featuring a snake's head at one end, with emerald eyes and sharp fangs. Jason Isaacs nailed the emotionally calculating father-wizard-Death Eater role onscreen, but while filming one of his very first scenes in "Harry Potter and the Chamber of Secrets," he accidentally injured Tom Felton ... with that cane.

Lucius and Draco didn't share a loving relationship, but Jason Isaacs has been fond of Tom Felton since the day he met him. The actor gushed over his co-star and onscreen son, during the "Harry Potter 20th Anniversary: Return to Hogwarts" HBO Max reunion special, referring to him as a "sweetheart."

In "Harry Potter and the Chamber of Secrets," Harry Potter escapes Privet Drive to go live with the Weasleys. Before his Hogwarts semester, the young wizard travels to Diagon Alley to purchase his books and other school supplies. Harry uses Floo Powder for the very first time and mispronounces his destination, which accidentally transports him to a store in Knockturn Alley instead. Although the movies rarely touched upon the location, it is established that not-so-great witches and wizards hang out there.

Harry finds himself arriving at Borgin & Burkes, an antique shop dealing with ancient wizarding artifacts. In the movie, Harry departs the elusive shop alone, but a deleted scene includes Lucius and Draco Malfoy, who enter the store while Harry hides in a case.

"Working with Jason was not always a treat, [he] just immediately turned into the most unfriendly, horrible person I've ever met," said Tom Felton in the special.

"I just remember grabbing him and being as unpleasant as I possibly could and watching his little face constantly seeking my approval," Isaacs added.

The actor continued, detailing the deleted Borgin & Burkes sequence, which shows his character's overbearing demeanor, and Tom Felton's professionalism at just 11 years old:

"The very first scene that I shot was actually cut, it's on the deleted scenes. Draco touched something, and I used this cane and went, 'Don't touch anything, Draco.' But I didn't know how sharp the teeth were, they went right into little Tom's hands. And he looked up at me, and his eyes welled with tears, and I went, 'Tom, I'm so sorry, I didn't realize how sharp they were and how heavy it was,' and he went 'It's all right, it's good for the scene.'"

Felton added: 

"He'd be this evil father, and when we'd say cut, he'd come and give you a cuddle and say, 'Oh did I hit you too hard?' Real Jekyll and Hyde that one."

Poor Tom. It looks like Jason Isaacs truly embodied those Slytherin House traits.