Nemesis: Sub-Terra
Nemesis Sub-Terra is a  drop tower dark ride located at Alton Towers theme park in Staffordshire, United Kingdom. The ride opened to the public on 24 March 2012. Its theme is focused on the discovery of a nest of eggs in a network of caves, an extension of the theme and concept of the park's Nemesis roller coaster that opened in 1994. After several years of operation, the ride closed abruptly in 2015 following a serious incident on The Smiler. Nemesis Sub-Terra, along with six other rides, remained closed the following season as the park transitioned into limited operation. Alton Towers later removed the attraction from its website in 2019, indicating it might be closed permanently. Following months of speculation in 2023, the park revealed that the ride was being refurbished, and it reopened on 27 May 2023. History
Plans for a new indoor drop tower ride were submitted in August 2011. Codenamed the Catacomb Project, construction began in September 2011 in the Forbidden Valley section of the park near the Nemesis and Air roller coasters (Air was renamed Galactica in 2016). Both the Body Zorb and Lava Lump rock-climbing wall attractions were removed to clear space. ABC Rides of Switzerland was hired to construct the ride, which would drop two stories underground and be based on their prototype Vertical Dark Ride concept. A similar drop tower ride opened as Extremis: Drop Ride to Doom at London Dungeon in 2007. Alton Towers marketed the ride as a horror experience, dropping subtle clues in an online campaign and installing heartrate monitors at the exit as a promotional stunt. The park billed the ride as "your worst nightmare underground", and it received a 12A rating from the British Board of Film Classification (BBFC), meaning children under the age of 12 would need to be accompanied by an adult. The concept art released depicted "blood-red tentacles and a bulging serpent's eyeball of the ancient malevolent creature emerging from a volcanic terrain" according to the Los Angeles Times. Jack Osborne, son of Ozzy Osbourne, was appointed Director of Fear for the attraction as an additional publicity stunt. In February 2012, Alton Towers released a promotional video of a bottomless lift, a hint about the upcoming ride. Nemesis: Sub-Terra opened to the public the following month on 24 March 2012. Themed as an extension of the Nemesis narrative involving an alien creature that emerged after being buried for two million years, the new ride was named Nemesis: Sub-Terra. The backstory involves a shady organization known as The Phalanx, who have discovered a nest egg underground believed to belong to Nemesis. The venue housing the ride is painted a military green, complete with staff dressing the part in military uniforms. The ride was tweaked after significant negative feedback from the general public. The changes to the ride were believed to have been implemented during the park's closure due to high winds on 4 April. However, this was not the case, as the entire site, plus other nearby attractions, was deemed unsafe because of the high winds and proximity to large trees, and the attraction was improved during planned maintenance sessions before and after the theme-parks normal public opening hours. Various trees were felled and cut back during the following weeks to improve safety in future bad weather. From 20 May 2012 the attraction closed for a period of six days in order to make improvements. Alton Towers Operations and Developments Director Mark Kerrigan revealed that the ride has yet to be officially completed by the park. Extended closure and reopening
In November 2015, as part of the downsizing of the theme park's operation in response to the Smiler incident earlier that year, Alton Towers announced that six of its attractions would not reopen the following season, including Nemesis Sub-Terra. The ride was eventually removed from the park's website before the start of the 2019 season, indicating permanent closure. During its closure in 2018 and 2019, the Sub Terra building hosted the scare attraction Project 42 for Scarefest, the park's annual Halloween event. The attraction made use of most the interior of the original attraction and was themed around a viral outbreak, where test subjects had developed animalistic qualities. Following months of speculation, the ride reopened on 27 May 2023. Ride description

As the entrance is approached, one of the Phalanx operatives shouts orders at riders to move into the batching area in a group of 40 in front of an entrance of two faux-lifts. Riders are then instructed to watch a pre-show video, which outlines the story of how one of the Nemesis creature's eggs has been made safe for viewing by the public. The Phalanx operative then makes a special warning to riders that there are live actors present throughout the experience and anyone uncomfortable with this should leave the batching area. Riders then move into the lifts, where it is further explained that it is travelling down an underground shaft, whilst lighting and sound effects create the illusion of subterranean travel. The lift door opens to reveal a cavern, or catacomb, just ahead of the main ride chamber – which remains sealed at this point. The cavern is themed with rock effects to give the impression of a recently excavated underground site. The main ride chamber then opens, and the aforementioned egg can be seen in the centre of the room, with four sci-fi-style zappers focusing upon it. Four rows of ten seats face the egg centre-piece and riders are ushered into the seats and told to pull down their lap bar with considerable urgency by the actors. Details of the discovery of the alien egg are then played via TV screens, and riders are told that it has recently been displaying signs of life. Midway through this presentation however, the TV screens cut out and lighting effects lead riders to believe that there has been some kind of power failure. Sirens then started to go off, and after a few seconds the lights go out altogether. The lights are then restored to reveal that the egg has hatched, and sound effects indicate that a creature is moving around the ride chamber. Each gondola then abruptly drops around 20 feet (6 metres) to the bottom of the chamber. The ride is programmed so that each gondola drops at a slightly different time to the others - to increase the tension for the rider. After the freefall, lighting effects reveal the other eggs that are unsafe to view. The riders are then put back into pitch-blackness, and slowly lifted up to where the main egg lies. Rapid light flashes occurs and water is sprayed at riders whilst more sound effects are played. 'Back pokers' and 'leg ticklers' surprise riders, giving the impression that the monster is in close proximity. Air bursts are activated, which blow onto the back of the neck of the rider, imitating the monster's close proximity. Sirens then begin to sound, and evacuation notices play, in which Phalanx operatives then quickly usher riders into the escape lifts. The lift begins to ascend, but shortly after the lights flicker before then once more, plunging the riders into pitch darkness. The lift then begins to shake and bang violently. A roof panel becomes dislodged and the wall panels move, simulating the alien creature attacking the lift and attempting to gain access. Once the lift doors open riders are greeted by a Phalanx operative wearing a scientific lab coat prompting guests to exit the facility. Guests pass cages containing an actor who bangs on the fence, and then enter the "decontamination zone", which was introduced for the 2023 iteration of the ride, replacing 2/3 of the final scare maze section present on the 2012-2015 iteration. References

External links
 Nemesis: Sub-Terra official mini-site
 Nemesis: Sub-Terra information on TowersStreet

Alton Towers
Dark rides
2012 establishments in England
2015 disestablishments in England
Amusement rides introduced in 2012
Amusement rides manufactured by ABC Rides
Amusement rides that closed in 2015