Real fans of Greenhouse Academy know whether they’re an Eagle or a Raven. Real fans know where their allegiances lie when it comes to the show’s many rivalries. Real fans also know that the show loves to leave audiences shocked with its crazy cliffhangers and huge revelations, as it did once again with the end of Season 4.But with all the twists and turns, some viewers are still unclear about what exactly happened at the end of Season 4 and what the ending means for the future of the show.Read on as we explain the Season 4 ending. Plus, find out why Grace van Dien left Greenhouse Academy so suddenly, even though audiences loved her portrayal of Brooke.A quick Season 3 recap of 'Greenhouse Academy':The end of Season 3, which premiered last year, had fans shook when a huge revelation turned the entire show on its head. In Season 3’s cliffhanger finale, audiences helplessly watched as Hayley and Leo discovered a cave under Greenhouse Academy while they were following a mysterious beeping sound.While looking for the origin of the beeping, Hayley mistakenly steps on a mine that had been left there as a trap! The pair try to escape but audiences only see Leo make it for sure, while Hayley appeared to be crushed by an onslaught on falling rocks.What happens at the end of Season 4 in 'Greenhouse Academy'?Thankfully, in Season 4, viewers were able to breathe a sigh of relief as Hayley found her way out of the cave. She also did so just in time, since the well-intentioned rescue efforts of her schoolmates led to the collapse of the cave’s roof that would have most certainly crushed Hayley to death.However, Hayley’s recovery after the cave incident is short-lived and the kids have to soon contend with a mysterious organization that is threatening them with the extraterrestrial virus from Season 3.By the end of Season 4, these masked men have taken over the academy and are about to unleash the virus that nearly killed Leo at the beginning of the season. Thankfully, the Eagles and Ravens decide to put aside their differences and come together against the masked villains and stop them from releasing the virus.Before the final credits roll, however, there is one more twist. Audiences find out that it’s been Brooke’s brother Jason, who’s been the mastermind behind all the evil schemes that have played out at Greenhouse Academy. \n\nViewers also see Jason standing in front of a mirror but being reflected back at him is a different face: the mysterious alternate conscience only known as The Client.Speaking of Brooke, why did Grace Van Dien leave in the middle of the series?Astute viewers may have noticed that the actress who played Brooke Osmond in the first two seasons of the show, Grace Van Dien, was conspicuously swapped out for another actress in Seasons 3 and 4.The reason Danika Yarosh became the new Brooke is that Grace Van Dien chose to leave Greenhouse Academy in order to take on a role as a series regular on The Village. \n\nAudiences can now watch her playing pregnant teen Katie, on the NBC drama that follows the neighbors of a Brooklyn apartment building as they navigate the challenges life throws their way, all while sticking together as a family.Grace’s talents will certainly be missed on Greenhouse Academy, but we’re sure Danika is up to the task of filling Brooke’s empty shoes. \n\nStream Season 4 of Greenhouse Academy on Netflix.