Fans of American Idol star Adam Lambert, and fans of hit US drama Pretty Little Liars, have double the reason to celebrate as it’s been revealed that not only is filming well underway for a new series of PLL, but the gorgeous Adam will guest star in the show’s Halloween special!

The Examiner reports that Adam will guest star as himself and will sing “at least two tunes” at fictional high school, Rosewood High, during the school’s Halloween party.

However, in addition, he’s set to “have a run in” with one of the four Pretty Little Liars – who are Aria (Lucy Hale) Hanna (Ashley Benson) Emily (Shay Mitchell) and Spencer (Trojan Bellisario) – at a pumpkin-themed party.

Some media outlets are reporting that Adam will play out a particularly important scene with Aria but that hasn’t been officially confirmed.

However, on Twitter, Adam confirmed, “Yup— imma be a Pretty Little Liar!”

PLL star Shay replied to his tweet, saying, “Welcome to Rosewood!!! ”

Pretty Little Liars airs on ABC Family on Tuesday nights at 8 p.m. Eastern Standard Time, but for those of you who’ve never seen it – and you really should, it’s brilliant – here’s a synopsis of what the drama is all about…

Set in the fictitious town of Rosewood, Pennsylvania, the series follows the lives of Spencer Hastings, Hanna Marin, Aria Montgomery and Emily Fields, four girls whose clique falls apart after the disappearance of their queen bee, Alison DiLaurentis (Sasha Pieterse).

One year later, they begin receiving messages from a mysterious figure using the name “A” who threatens to expose their secrets. At first they think it’s Alison herself, but after she is found dead, the girls realize that someone else knows their secrets—including long-hidden ones they thought only Alison knew.