Sean Biggerstaff had a small role in the first two Harry Potter movies, but his bond with Alan Rickman evidently went deeper than we thought.

Alan Rickman died yesterday, very unexpectedly, at the age of 69. His passing shocked the world, and his fans and colleagues have been paying their respects on social media, grieving together and remembering Rickman’s most iconic performances.

One of Alan Rickman’s most memorable roles was that of Severus Snape in the Harry Potter movie series. Rickman played Snape in all eight films, and was seemingly close with everyone on set: J.K. Rowling and the saga’s three main stars Emma Watson, Daniel Radcliffe and Rupert Grint have all posted tributes to the beloved actor.

Related: Hypable remembers 5 of Alan Rickman’s best roles

Many other Harry Potter actors have been sharing their Rickman memories, too, but we weren’t expecting one particular tribute to be so moving and memorable.

Scottish actor Sean Biggerstaff only appeared in the first two Harry Potter movies, Philosopher’s Stone and Chamber of Secrets, playing the Gryffindor Quidditch team’s captain and Keeper.

Biggerstaff had no scenes with Alan Rickman, but as we’ve learned, Rickman was actually instrumental in him getting the part.

Biggerstaff wrote on Twitter, shortly after the news of Rickman’s passing broke:

He also shared a link to this great clip of Rickman:

What few people know is that Biggerstaff and Rickman did not meet on the set of Harry Potter. When he was only 14, Biggerstaff appeared in a movie directed by Rickman, titled The Winter Guest (1997). The movie also starred Rickman’s frequent collaborator Emma Thompson.

And evidently, Biggerstaff and Rickman didn’t sever their connection after Potter.

His tweet was followed by a TwitLonger post about his long-standing friendship with Alan Rickman, and how Rickman not only helped kick-start his career, but supported and encouraged him every step of the way.

We definitely recommend reading the full thing, but here’s a poignant highlight:

When my friend Donny wrote a play that he wanted me to be in, I sent it to Alan, hoping for some advice on where we might get it put on. He received it when he was stepping on a plane. When he landed he emailed me back, having read the whole thing and loved it. Two days later we received a printed copy of the play with mountains of suggested edits, cuts and thoughts scrawled across it in his handwriting, and a two page letter with praise for Donny and advice on who to take it to.

He did the same for the next four drafts. This. Never. Stopped. In twenty years, all my experience of Alan was like this. He’d be on a mad press trip round the world, having just finished a broadway show and be about to start shooting a film – with several other projects as an actor, director, writer, board member, mentor bubbling away in the background – and if I needed anything he would immediately spend hours of his time helping me. AND, amazingly, I know of at least a dozen other people who had this same relationship with him. He was our fairy Godfather. He was the whisper in the right ear at the right time. He was the reassuring message when he sensed, always correctly, that we needed it most. He was new head shots or carpets or travel money when times were tough. How he found the time, let alone the will for all this is a mystery to me. He was the most generous, wise, supportive, talented, charismatic, empathetic person I think I’ve ever known.

As sad as we are about Alan Rickman’s passing, it’s nothing compared to the sadness those who knew him personally are feeling. All our love to Sean Biggerstaff, and everyone else grieving the loss of Alan.

Related: Fans pay tribute to Alan Rickman at Hogwarts, Platform 9 3/4, and online