It's the semi-final at the Brit Awards! The MUAs will be working under pressure and against the clock, as this week they are working on four demanding celebs whose looks need to be perfect before they step out and hit the wall of paparazzi.Guest judge Hector Espinal – MUA to celebs such as Rihanna and Halle Bailey – has flown in to keep a close eye on the MUAs, and he's also at the ready to step in should the looks not live up to his or the celebs' standards.One MUA builds confidence throughout the make-up, and her pink princess celeb leaves the chair feeling a million dollars, but the opposite happens for another MUA, whose honesty about being in the red chair numerous times leaves their celeb a little nervous.Hector's flight over does not go to waste, as one MUA's work comes undone before it even steps out onto the red carpet, forcing Hector to step in!The next day in the Glow Up studios, with the pictures of the celebs all over socials and the papers, the judges discuss which MUAs failed to impress.For their semi-final creative brief, the MUAs must produce looks showcasing their greatest hits. Two MUAs draw upon their university projects to try to wow the judges and secure their final spot. Another recreates a look which was picked up on online by none other than Nikkie Tutorials, who then took inspiration from their look for her own Halloween look. And one MUA incorporates their two passions: hairdressing and make-up.Following judging, two MUAs head into the Face-Off elimination where, against the clock, they are asked to produce a spider lash. With the stakes high for a place in the final, it becomes a very tough decision for the judges.