"Three Days of Indigo" by Sergei Lukyanenko, summary Automatic translate

"Three Days of Indigo" is a 2021 novel by Sergey Lukyanenko, the second book in the "Changed" series, continuing the events of "Seven Days to Megiddo." The action takes place in post-apocalyptic Moscow, where the alien Insec has destroyed the Moon, turning it into a Lunar Ring containing large fragments — Selena and Diana. Mobile communications and the internet are banned, Nests of the Changed — terminally ill children mutated by an alien mutagen — have appeared in cities, and alien Sellers trade with humans in crystalline structures called Lumps. The novel is structured like a detective story: the investigation into a murder, impossible by any standards, unfolds step by step over three days, ultimately leading the protagonist beyond Earth.

Night call

A young searcher — a seeker of alien crystals — Maxim Vorontsov lives in central Moscow and develops an unexpected relationship with the reaper Darina, a Changed One from the Nest on Gnezdnikovsky Lane. Reapers are a type of Changed One who act as caretakers for dolls: Darina’s eyes are filled with a lilac glow, her skin is perfectly smooth, and she possesses the ability to easily kill a person with her bare hands. Maxim wants only one thing: a reversal mutagen capable of transforming the reaper back into an ordinary girl. He knows that the Sellers trade in anything, from a statue of the Venus de Milo to rare medicines.

At half past twelve in the morning, a young searcher named Seryoga from Bolshaya Bronnaya calls the intercom: The seller has asked me to urgently tell him he has something Maxim "really needs." Maxim goes to the Komok on Tverskoy Boulevard. The seller gives him a choice of two goods: complete information on the nature of the aliens — the Old Ones, the Insecs, and the Sellers themselves — or a reversal mutagen for one Altered One. Maxim doesn’t hesitate for a second. He chooses the mutagen.

Dead Man with an Axe

His reward is a murder investigation. The previous evening, between nine and eleven, a Salesman was murdered in the Komok on Shlyuzovaya Embankment. Neither the police nor the city authorities know about it. The Salesman explains why he can’t go to the authorities himself: they are swarming with the Former Ones, who hate the Salesmen for once helping Insec establish control over Earth. His request is simple: find out who killed him and how — and report it. The Salesman doesn’t ask Maxim to fight the killer: he understands that such an enemy is beyond Maxim’s capabilities.

In the morning, Maxim arrives at Shlyuzovaya. Naska, a ten-year-old doll from the Nest, tags along with him, using a game of hide-and-seek as an excuse. She’s energetic, has read every detective story in the world, and has undergone a very slow mutation, having lain motionless for years among the books of the Ministry of Culture. She’s spontaneous, unstoppable, and unexpectedly useful. Leaving her in Moscow is impossible: dolls are stronger than adults, and Naska skillfully evades any attempt to return her to the Nest.

In the Lump, on the embankment, they discover a dead Salesman. Beneath layers of rags are metal pins where his legs should have been, and corrugated metal where his wrists should have been. A ten- to twelve-centimeter-long hole protrudes from his chest, filled with a solidified blue, viscous liquid. A common carpenter’s axe with a wooden handle lies to the side. Salesmen are mechanical beings, robots, and someone knew this well enough to come to the Salesman with an axe.

Team

Maxim calls Colonel Likhachev, the head of the "Ex" department, who has been investigating aliens for many years. He reacts immediately: the sight of the disassembled Salesman literally shocks him, but his professional passion takes over. Elena, a surgeon skilled in performing an autopsy, and Milana, a biology student who proves unexpectedly versatile, join the investigation: as a child, she soldered her own radio, and also practiced fencing and is an expert with a rapier.

The autopsy confirms: before them is a mechanism unparalleled on Earth. The blue liquid is an alien equivalent of hydraulics. The murder was committed by a precise strike, one that knew the anatomy of these creatures. Everything points to the Former Ones — a hostile race that tried to confront Insec back during the Change and lost, but did not disappear. The Former Ones can act through people, infiltrate power structures, and remain invisible — but wielding a carpenter’s axe in an alien Lump? That’s almost demonstrative audacity.

On Selena

The investigation leads Maxim to Insec’s ship, hovering over the far side of Selena — the largest fragment of the former Moon, with a wide, conical section facing Earth. They board, have a brief conversation with Insec — an enormous, dying creature gradually immersed in its "healing procedures" — and receive spacesuits and rapiers from Maxim and Milana.

The spacesuits are unlike anything else: metal sleeves and legs, a gray, pimply fabric shell, a transparent helmet instead of oxygen tanks — more like a child’s cosmonaut costume than serious equipment. The rapiers are classic combat rapiers, with a half-guard, made of blue-gray naval metal. Milana, to Maxim’s surprise, holds the weapon confidently: her hands remember. The soles of the spacesuits are held to the surface by adhesive hairs, like the feet of a gecko.

There’s almost no gravity on Selena. Maxim learns to move by leaping — like a kangaroo, several meters high and tens of meters forward in a single leap. The spacesuit resists, trying to steady his legs with each landing, and Maxim repeatedly slams his helmet into the rocks, cracking his forehead. Gradually, the spacesuit "breaks in" and begins to assist, absorbing the impact of landing and providing further thrust. Maxim accelerates to thirty to forty kilometers per hour, racing across gray rocks, flying over cracks and craters, with the Earth hanging behind him.

Fight

Meanwhile, two lights appear on the map in his helmet near the ship: green and red. Green is Milana’s, red signifies disaster. She couldn’t handle the enemy alone. Maxim abandons all his movement reserves and leaps toward the ship. A shameful thought flashes through his mind: if Milana dies, the torturous love triangle between him, the reaper, and the biology student will end on its own. He dismisses it as cowardice.

Milana’s opponent turns out to be Nika — the Former One, who came to Selena for a reason. It was this line that explained the murder in the Lump: the Former Ones had been acting not only through people but also directly, and the axe in the Seller’s chest is their signature, their demonstrative response to those who once helped Insec drive them from Earth. A rapier duel in a vacuum — no air, no sound, only the clang of metal through gloves and the reflection of Earth on helmets — becomes the culmination of a three-day investigation.

Maxim makes it in time. The battle is over. The mission is complete: the killer is identified, the information is passed on to the Seller. The return mutagen is transferred to Maxim — the very thing he’d spent three days trying to obtain, from his nightly visit to the Lump on Tverskoy Boulevard to his leaps across the rocky fields of Earth’s dead satellite.