The stars of the new Harry Potter film are expected to wear white ribbons on their wrists at the movie's world premiere as a mark of respect for murdered actor Rob Knox.
Knox, 18, who played Marcus Belby in the latest Potter adventure - Harry Potter And The Half-Blood Prince - was stabbed to death outside a bar in Sidcup, Kent, last May, just days after completing the film.
The actor was defending his younger brother when he was attacked by Karl Bishop, who is now serving four life sentences for the murder.
The glamour of the red carpet premiere in London's Leicester Square will be tinged with poignancy as the cast and crew show their solidarity with knife crime victims by wearing the white ribbons.
Knox's family watched a special screening of the Half Blood Prince at the weekend, and his mother Sally said she was "immensely proud" of her son.
The sixth instalment of the wizarding saga sees wicked Lord Voldemort tighten his grip on the worlds of Muggles and wizards and even Hogwarts is no longer the safe haven it once was.
Professor Dumbledore and Harry work to find the key to Voldemort's defences, enlisting the old wizard's friend Horace Slughorn to help with the task.
Elsewhere, the Hogwarts students find themselves under attack from a very different type of foe, as teenage hormones rage throughout the school.
Harry, played by Daniel Radcliffe, finds himself drawn more and more to best friend Ron Weasley's sister Ginny, while a box of chocolates laced with love potion throw matters into confusion.