Paradise Towers Paradise Towers was a residential building complex in the 21st century . History . Early history . Paradise Towers was designed by Kroagnon and had won several architectual awards . The motto of Paradise Towers was " build high for happiness " . As with many of his earlier projects , Kroagnon refused to leave once his work was done , nor let people move in . Some of the residents imprisoned him in the basement , aware he would kill everyone in the buildings should he escape . The cleaner s – robots , designed to keep Paradise Towers clean – stayed active . When war broke out , the young and the old were transported to Paradise Towers , while those in between went off to fight and never returned . The caretakers were exempt from this military service and stayed at their jobs . Pex avoided the war by hiding aboard one of the ships headed for Paradise Towers . The residents of Paradise Towers began to diversify . The young girls became known as Kang s and were themselves grouped into Red Kang s , Blue Kang s and Yellow Kang s . The old women became known as Rezzie s — a distortion of the word resident ; many of them turned to cannibalism , eating Kang s and Caretakers . The Caretakers themselves tried to control Paradise Towers and keep it clean . The cleaner s were feared by all the groups , though the Chief Caretaker secretly used them to feed Kroagnon by killing people in Paradise Towers and taking the bodies to him . Defeat of Kroagnon . The Seventh Doctor and Melanie Bush visited Paradise Towers and met the Red Kangs . They took a liking to the Doctor , but were unsure about Mel . An attack by the Caretakers resulted in them getting separated . Mel found herself with two Rezzies , Tilda and Tabby , while the Doctor was taken prisoner by the Caretakers . The Doctor quickly escaped his captors by tricking them with their own rulebook and Mel decided to head for " the pool in the sky " with Pex for company , as that was where she had agreed to meet the Doctor . The Cleaners tried to re - capture the Doctor . They sent a team to break into the Red Kang brainquarters , where he was hiding . They took him to the Chief , who interrogated him . Meanwhile , Mel again joined Tilda and Tabby , but they took her as a prisoner to eat her . Before they could do so , a cleaner dragged them both through a waste disposal unit and killed them . From there , Mel and Pex made their way to a lift but were trapped in as the Kangs had been known to press the buttons up and down the shaft so the lift didn ' t stop . Eventually , Pex fixed the lift and they arrived on Floor 304 — the top floor of Paradise Towers — and settled down to wait for the Doctor . Mel decided to take a swim in the pool and found herself under attack from a water - bound cleaner . She destroyed it with Pex ' s gun . The Doctor was rescued by the Red Kangs and they returned to the brainquarters . The Blue Kangs entered and proclaimed victory over the Reds for breaking into their base . The Doctor convinced them to work together against Kroagnon and they headed for the basement . Kroagnon needed a body into which he could place his mind through corpoelectroscopy . He chose the Chief for this and took control of his body by forcing him into a special chamber in the basement . The Doctor witnessed this and was attacked by a cleaner . He was pulled free by the Kangs and they fled . Kroagnon had the cleaners gas each floor of Paradise Towers in turn , steadily making their way upwards . The Doctor took the Kangs to Floor 304 and they allied themselves with Pex , the Rezzies and Caretakers , who had also been forced upwards . With a combined effort , the Kangs and Rezzies destroyed several cleaners . The Rezzies trapped them with tablecloths while the Kangs destroyed them with explosives . To deal with Kroagnon , the Doctor asked Pex to lure him from the Chief Caretaker ' s office where he had based himself . Pex was to lead him slowly to a designated area where they would spring a trap on him . Pex was fearful of Kroagnon , and led him to the location too quickly . The Doctor tried to push Kroagnon down a life shaft , but wasn ' t strong enough . Kroagnon began throttling the Doctor and smashing him against a wall . Pex took a lit stick of explosive and jumped into the lift shaft , taking Kroagnon with him . The resulting explosion presumably killed them both . The united factions of Paradise Towers held a ceremony in his honour . The Kangs gave the Doctor a red and blue scarf to denote him as an honourary Kang . As the TARDIS dematerialised , a wallscrawl behind it said , " Pex lives " . ( TV : " Paradise Towers " )