You don't recognize it? This is your home! The Great Clock! A marvel of science and sorcery, engineered by the brightest Zoni in all of existence and constructed in the exact center of the universe! Give or take fifty feet.
The Great Clock, also known as the Keeper of Time, is a Zoni construct located in the exact center of the universe (give or take fifty feet) near the Breegus Nebula, in an uncharted system at the edge of the Polaris Galaxy. Designed by Orvus to maintain temporal normality across the universe, Clank was brought to the Clock by the Zoni to be its inheritor at the request of his father. Due to the Clock's power over the time continuum, it was sought after by numerous parties who wished to use it to change history.
The computer that governs the Great Clock runs on PK-17 sisterboards with a raritanium vector shell. The only other computer with this setup was IRIS. The Great Clock itself has over 4.3 trillion moving parts, making it the most complicated piece of machinery in the known universe. Second was the IRIS Supercomputer, followed by a terachnoid juice maker.
117,000 Zoni guarded and maintained the Great Clock before Nefarious set his Hypersonic Brainwave Scrambler loose and dwindled their numbers to 305, and later 120. Ratchet was able to rescue 40 scattered Zoni throughout the Breegus System with the Zoni Vessel and returned them to the Clock, where the rest of the Zoni appeared to return to in the end.
While the Clock governs time, it is not intended to be used as a time machine, with its maximum safe time reversal period being 6 minutes.
Eons before the events of A Crack In Time, the fongoids were entrusted with the gift of time travel by the Zoni in the hopes that their lives would be enriched by the experience. However, the blatant misuse of that power began to break down the space-time continuum, resulting in a tear that caused 83 celestial bodies to be destroyed in the ensuing anomaly.
Sensing the danger to the universe, Orvus designed the Great Clock to repair the damage and ensure that time could no longer be threatened. He would then watch over the flow of time itself from within the Orvus Chamber, the central control room of the entire facility that contained a master switch in case of an emergency.
Kaden was the one of the first outsiders to theorize of the Great Clock's existence based on translated runes found on Quantos.
After the defeat of Emperor Tachyon, Clank was kidnapped by the Zoni that had helped him to survive in order to fulfill Orvus' wishes of leaving the Clock in his care. Unfortunately, Clank was damaged by exposure to Zoni energy and they were forced to contact Dr. Nefarious in order to fix him. Nefarious used the front of their partnership to search for the key to the Orvus Chamber that was located somewhere in Clank's brain, but quickly lost patience with the Zoni trying to stop him and unleashed the Hypersonic Brainwave Scrambler and his troopers to attack them. In the ensuing chaos, Clank woke up and attempted to escape, but was quickly incapacitated.
Thanks to Nefarious' inventions, the Clock was severely damaged and time distortions began to appear on numerous planets throughout the galaxy. After waking and befriending the Clock's Junior Caretaker Sigmund, Clank was tasked with repairing these distortions and learning of the Clock's true purpose. He also was given numerous messages left behind by Orvus, claiming that using the Clock improperly as a time machine could rip the universe apart.
After reuniting with Ratchet and defeating Nefarious, the Great Clock was once again put in jeopardy by Alister Azimuth, who wanted to use the Clock to prevent Tachyon's attack on Fastoon and save the Lombaxes. Enraged at his own kind denying him the chance, Azimuth killed Ratchet and forced Clank to flee to the Orvus Chamber in order to stop him initiating a shift. Though initially conflicted on what to do, Clank remembered earlier advice given to him by the Plumber and used the Clock's master switch to reverse the flow of time for six minutes, preventing Ratchet's death.
In the new timeline, Azimuth would once again try to seize control of the Clock, initiating a shift and destabilizing the facility in the process. Realizing that his actions were threatening to destroy the Clock and the universe with it, Azimuth sacrificed himself to reverse the shift. Following the battle, Clank changed his mind on intending to stay in the Clock, realizing that he could not leave Ratchet alone, promoting Sigmund to be the Clock's Senior Caretaker in his stead.
The Great Clock was split apart into different Sectors that were responsible for different functions of protecting time, though only five are ever explored in game. It held a number of different Planet Rooms which Clank used to fix various time distortions on the surface of such planets. Fixing these distortions would in turn allow Ratchet to access parts of these planets that he was unable to do beforehand. The planets that could be fixed were Jasindu, the Kreeli Comet, Quantos, Torren IV, Terachnos and Fastoon.
Great Clock: Sector One is a large corridor that surrounds the Polaris Planet Rooms and has several corridors leading away from it to areas such as the outside hubs. Clank had to escape through this Sector upon waking up after his capture, using the damaged time distortions and Sigmund's help to escape.
Great Clock: Sector Two consists of numerous buildings located outside the Planet Rooms, connected by jump pads and floating platforms. To ensure Clank was ready to take care of the Clock, Sigmund educated him about the usage of temporal recording in order to progress. After making their way to a mnemonic station, Clank conversed with a digital simulation of Orvus, who taught him about the Chronoscepter he would later be gifted with. The Hypersonic Brainwave Scrambler was also destroyed upon leaving the Sector.
Great Clock: Sector Three is a hub of Planet Rooms containing numerous planets located in the Polaris galaxy. Clank utilized these in order to repair the time distortions that had appeared. Sector Three also contained the Orientation Room, where Clank was shown a video explaining his duties as Senior Caretaker, though Sigmund claimed it's primary use for him was watching cartoons.
Great Clock: Sector Four is primarily a pathway leading to one of the final mnemonic stations and the Orvus Chamber, though does contain a hidden Planet Room related to Fastoon.
Great Clock: Sector Five was near the center of the Clock itself, composed of the Orvus Chamber and the contents within. It was here that both Ratchet and Clank chased down and fought against Azimuth as he risked existence itself to try and correct the past.
Behind the scenes
Despite Orvus' warnings of never using the Clock to change time because of the danger it poses, both Ratchet and Clank use time portals generated by the Clock in order to influence past events and change history in a contradiction. A potential explanation for this could be in how this travel occurs. As the time portals are only ever generated when a time distortion is already present on a planet, they are a side effect of damage that the Clock has undergone. Orvus also specifically warns against using the Clock itself as a time machine, implying that Azimuth's attempted shift near the end of the game is affecting the flow of time for the universe as a whole, rather than just utilizing a hole in time that it already there.
The Great Clock appeared as two spaces in PlayStation Home named "Time Travelers" (main space) and "Home Sweet Home" (personal space).