Roderick Gordon, Brian Williams

Cover artist

David Wyatt


United Kingdom


Science fiction
Subterranean fiction

Publication date

UK: September 1, 2011
US: May 1, 2012



Preceded by


Followed by


 Spiral Is the fifth book of the Tunnels Series. It was released in Great Britain (England) in September 2011, and was published in North America and the USA in May 2012. It was preceded by Closer and followed by Terminal.


Part 1: The Phase

After the events of Closer, Colonel Bismarck, deprogrammed by an explosion during an attack on the Bank of England, decides to help defeat the Styx, and joins Will and Drake at Parry's estate. Drake introduces Will and Chester to 3 retired commandos living at the estate: "'Sparks" Sweeney, who was surgically altered to have enhanced senses and faster reaction times, Danforth, a genius who worked in defense electronics, and Jiggs, who is good at hiding. Will also meets Parry's gardener, Old Wilkie, and his granddaughter Stephanie. The people of the estate watch for Styx presence, and eliminate the Dark Light conditioning with the help of a device called the Purger, invented by Danforth. The Purger causes a Darklit person to repeat part of their progamming, and Elliott, who is able to speak Styx, finds that Chester has been programmed to call the Styx and report their location. Meanwhile, the Hunter cats Bartleby and Colly are hunting when they encounter 2 Limiters spying on the manor; Bartleby is killed and wound Colly. Will and the group decide to leave when Mrs. Burrows detects Limiters entering the estate. They escape, only to be cornered by Eddie, who reveals the Limiters, rogues like him, are under his control. He was the one Chester was reporting to, and he saved Chester's mother Emily from being used as a terrorist by the Styx. Meanwhile, in The Colony, the Second Officer is worrying that the Styx are neglecting the Colonists to focus on their Topsoil plans. Many people have been moved to a violent and unruly shantytown in the North Cavern to make room for the New Germanian army, and people are disappearing. Topsoil, various terrorist attacks are made by Darklit people who have had bombs surgically implanted within them, and these "human bombs" kill foreign politicians to stir up hatred of Britain. At a factory bought by the Old Styx, the Rebecca twins have brought several hundred humans and Darklit them to render them brain-dead. They have also brought the Styx females, who are undergoing part of the Styx life cycle called The Phase. (For more information on The Phase, see the page for it.) Upon learning this, Drake and the group decide to take action. They set up headquarters in a military base known as The Complex, a bomb shelter for the UK High Command during the Great War. Strong anger has arisen worldwide over the "human bomb" attacks originating from Britain, and many countries (including the USA) cut off their connections to Britain, which closes its borders and puts itself under martial law. Underground, the Styx abandon The Colony and seal the exits after evacuating the shantytown residents as hosts for The Phase. Finally, Eddie is brought back to base where Elliott angrily attacks him.              

Part Two: Maelstrom

Elliott is examined by Danforth to make sure that she isn't being affected by the Phase, as it is uncertain whether or not she can take part in it as a Styx/human hybrid. Danforth announces that she should be safe for now, although that may change when she finishes puberty. In the Colony, the First Officer decides to quit after someone tries to burn the Colony's police station down. His last act before promoting the Second Officer to head the Colony's police is to set the prisoners in the Hold free. Topsoil, Elliott and Stephanie bond as the group tries to think of ways to find the Phase. They decide to use Drake's computer program to find where people are being Darklit, but cannot think of a place high enough to survey the entire country until Sergeant Finch, the Complex's caretaker, suggests the BT Tower in London. Danforth creates mobile Dark Light detectors out of the Geiger counters lying around the Complex, which Parry distributes to the Old Guard, an organization of ex-commandos that he can call upon in a time of need. The group travels to London via a Chinook helicopterand a disused subway line meant to ferry High Command to the Complex if war broke out. At the Tower they direct the Old Guard searchers to where Dark Light activity is detected, which is everywhere as the Styx are trying to destabilize England to make way for their invasion by starting riots. When one of the Old Guard finds a factory in Slough guarded by Limiters, New Germanians, and Darklit Topsoil soldiers, Parry decides to have the Old Guard attack there.

Part Three: Assault

The Rebecca Twins' argument over Rebecca Two's crush on Captain Franz is interrupted by a phone call warning them about the impending attack. They leave the factory, taking with them two of the Styx women, Vane and Alex, a pair of twins who were role models to the Rebecca Twins as they grew up. The Old Guard's attack on the factory goes almost flawlessly, wiping out the Warrior Larvae and the Styx women. To guard against the Armagi, they use incendiaries to destroy the factory. Watching the explosion, Vane, Alex, and Rebecca Two are despondent, but, as the mysterious warning call turns out to have come from Danforth, he had told Rebecca One what to do to ensure the spread of the Warrior Class: Rebecca One and Vane will go into the inner world, while Rebecca Two and Alex will stay Topsoil to induce the older Styx girls who may be far enough along in puberty to join the Phase. When the group returns to the complex, they review the security camera footage from the factory, where they discover the Rebecca Twins' escape. Meanwhile, Chester notices that his mother isn't acting normal. When the group asks Danforth to trace the call that warned the Rebecca Twins, he tells them that he made the call. He became convinced that the Styx were more highly evolved than humans after he translated the Book of Proliferation, a Styx text about the Phase that Eddie gave the group. Embittered by the government exiling him to Parry's estate in exchange for all his hard work for them during the Cold War, he tells them that the Styx are making him the director of their research efforts in exchange for him giving Rebecca One the idea about the inner world. He tells them that Emily Rawls, whom he Darklit, will cover his escape with a suicide vest. As Danforth flees, Jeff Rawls, convinced that he can persuade his wife to stand down, approaches Emily Rawls. She responds by detonating herself, collapsing the only way out of the Complex. Elsewhere, Rebecca Two and her grandfather, the Old Styx, have taken over a health spa in Kent, and are using it to breed more Warrior Larvae and induce the older Styx girls. Meanwhile, in the Complex, the mood is dire: they, the only ones who know that the Phase is still going on, are cut off from the outside world and only have two weeks worth of air left. With their time almost up, Drake and Eddie formulate a desperate plan: use the explosives stored in the Complex to blast through the side of the mountain. While the group fetches the explosives, Parry reveals that the Complex is being used to store obsolete nuclear bombs. In the inner world, Rebecca One arrives to learn that the high levels of UV lightin the inner world has greatly accelerated the Styx life cycle: Vane has implanted egg sacs in over 300 humans in one day, the Warrior Larvae are already hatching, and Vane has grown two additional ovipositors and pairs of insect limbs. Topsoil, the group's plan works, and they escape the Complex. Parry's reveal of the nuclear weapons has given Drake an idea: use two of the devices to seal the passageways to the inner world.

Part Four: Nuclear

Half of the group (Drake, Mrs. Burrows, Sweeney, Jiggs, Will, Elliott, Colonel Bismarck, and Colly) use a stolen British Gas van to gain access to the house formerly owned by the Burrows family before their disappearance, and, more importantly, the tunnel to the Colony beneath it. When the group reaches the Colony, they arrive just in time to help the new First Officer and the freed prisoners overthrow the Governors, Colonists appointed by the Styx to positions of power as the Styx's puppets. While in the Colony, Mrs. Burrows decides to stay in the Colony, as she is blind, as well as Colly, who is pregnant with Bartleby's kittens. Also, Drake reveals that he possesses a second weapon of mass destruction: a virus that kills all mammals, including humans and Styx, that he stole from the Laboratories before he destroyed them. In return, the Colonists provide them with transport to the Deeps, where the Pore leading to the inner world is located. At the Pore, the group steals a Coprolite digger from the Limiters, who were using the Coprolites as slaves to dig a tunnel to the inner world. The group then use the digger and some mini-rockets designed by Drake to travel to the inner world. After they have planted the nuclear weapons, the group is about to exit the inner world when they are ambushed by Rebecca One, Vane, and a patrol of Limiters, killing Colonel Bismarck. Jiggs evens the odds when he emerges from hiding and kills one of the Limiters before being wrestled into the void by another, distracting the Styx long enough for Sweeney to kill the other Limiters. Seeing victory turn to defeat, Rebecca One tries to kill her old nemesis, Will, but Drake wrestles her into the void before she can shoot Will. Sweeney takes Vane hostage as a guard against Styx reinforcements. As Rebecca One and Drake fight as they fall through the void, Drake, thinking he is dying, detonates the explosives, presumably killing both of them and sealing the inner world. The electromagnetic pulse from the blasts overloads the circuitry in Sweeney's head, killing him. As he falls, he crushes the test tube containing the virus, releasing it into the inner world. The virus kills all of the mammals, humans, and Styx in the inner world except Will and Elliott, who were vaccinated for it in the Complex. Topsoil, while the other half of the group searches unsuccessfully for the site of the Phase, Chester has fallen into a deep depression over the deaths of his parents.


Rebecca Two's mourning over her twin sister's death is interrupted as the Armagi begin to hatch.