The river was deep here, too deep to wade, and the water had a strong metamorphic effect. Any necromancer who spent any time in its waters would find both body and spirit changed, and not for the better. Any Dead Spirit who managed to wade back this way would not resemble its once-living form.
Abhorsen Garth Nix pg 275 1st ed.

Rushing after the small spirit that was her daughter, Chlorr, Abhorsen, did not pay attention to where she was in the Second Realm, and plunged into a hole. Coldness leeched into her, and she lost control. Breaking the surface of the dark river again, she screamed.

The midwife's hair hung in her eyes, and she blew it out of the way with a puff of air. She set out strips of cloth and towels, preparing for the impending birth. "It will still be a while yet."
Chlorr winced in pain as another contraction rippled through her abdomen. Gasping for breath, she gripped the blanket she lay on. Panting, she lost sight of the midwife who was leaving to fetch the town's Charter Mage. Chlorr closed her eyes, shutting out the view of the beamed ceiling of the midwife's hut, and waited.
When the midwife returned in a few moments, she was muttering about what a shame it was that Settyen was not here to witness the birth of his child.
Crying out in pain, Chlorr bucked on the bed. When the contractions had subsided for a bit, the Abhorsen glared at the older woman. "Everyone and everything has a time to die."
"I apologize, Mistress," The midwife said humbly as she swabbed Chlorr's forehead and cheeks with a cool, damp towel, wiping away the perspiration accumulated by the efforts of the labouring mother.

"Oh, Charter help us," The midwife whispered. The child's feet came first, and she could see as the birth progressed that it was a girl child. "Bear down, Mistress, she's almost there!" Chlorr wailed, begging the Charter to end the pain. Clutching her knees, she lifted her head off of the blanket, staring blankly at the midwife, who was looking worriedly at the baby. Her jaw clenching, she squeezed her eyes shut and bore down, pushing hard.

"What's wrong with her! Is she alright?" Chlorr was propped up on her elbows, ignoring the pain, for her child was not crying. The midwife was wiping the nose and mouth of the child out with a strip of soft cloth. She seemed very afraid to look at the new mother. Turning the baby upside down, she held her by the ankles and slapped her buttocks briskly.
"The birth took too long, I think," the midwife said in an undertone. But as she spanked the child, a weak mewling sound was heard. Soon, this keening strengthened to a louder cry. Lying back down on the sweat soaked blankets, relieved, Chlorr held her hands out to her daughter. The midwife sighed contentedly, wrapped the new child in a blanket, and handed her to her mother.
The midwife went to fetch the Mage, who would baptise the infant. Chlorr watched her child nurse, smiling. "I do wish that Settyen were here. He would be proud to see his beautiful little girl. You are all I have left of him."

A fortnight later, the servant of Abhorsen felt the wards on the House ripped asunder. Sethern, the newborn, the only child of the current Abhorsen, slipped quietly into the cold river of Death. Mogget had felt it. It was only a slight happening. The wards were not touched, it was a natural death. Creeping silently, Mogget's yellow eyes peered at the sleeping Abhorsen. Sethern's feeding time would arrive soon, and so Chlorr would wake shortly. Funny, that the death of the child did not disturb her. Wake her now, or wait for her to find her heir dead on her own? Mogget debated with himself. What would benefit him? Cocking his head to the left, he studied the Abhorsen. Perhaps he should wake her. As he moved, Chlorr awoke on her own. Suddenly, she leapt out of bed and ran to the small cradle. Before Mogget could react, Chlorr had thrown herself through the wards and barriers and into Death, her body frosting, ice falling to the floor.
Hissing and spitting, Mogget dashed to the bassinette. He jumped up on it, casting a cursory glance at the baby's body, still and pale. He could feel the doorway into Death, and he crossed it warily.

The cold water swirled around his robe at the beginning of the First Presinct. He appeared in Death as he was, a blue-white luminescence, much taller and thinner than any man. The Free Magic creature Mogget wore the white robe emblazoned with the silver key symbol of the Abhorsen, and a red leather belt, swimming with Charter Marks, buckled with a miniature Saraneth. Almost casually, he watched this doorway into Life, guarding it against any denizens of Death and awaited the return of the Abhorsen.

Abhorsen's feet fell from under her, and she slipped into one of the many pits in the Second Realm. Reaching the surface again, screaming, gasping, Chlorr spotted the small bundle that was her daughter's spirit being swept into the Second Gate. There was not much Chlorr could do, as she herself was being taken there herself. The current had her in its merciless grip. Plummetting through the Gate, spinning in the whirlpool, desperately trying to see her daughter again, Chlorr relaxed, letting the vortex take her. The small bundle drew closer as the water brought Chlorr to the Third Presinct. Shrieking, she reached for Sethern, but the waves in the Realm separated them, and a large wave smashed Chlorr through the gate, and down the waterfall. In the Fourth Realm, she had no footing, and the current carried her and her child to the next waterfall and into the metamorphic waters of the Fifth Presinct.
Chlorr cried out as the water touched her. It was not the cold, leeching feeling of the waters of the previous presincts, but a corrosive heat that Chlorr felt in her flesh and spirit. Feeling for the Charter, she desperately tried to think of a spell to save herself. She could not feel the warmth of the Charter and so, throwing back her head, she screamed out the Free Magic spell that Abhorsens and necromancers alike used to cross this horrible district of Death, and Chlorr felt the path suddenly beneath her feet, lifting her up out of the water. Shuddering, choking, retching on the metallic taste of Free Magic, Chlorr rested on the narrow path briefly. Slowly, she started back towards Life, reluctant, but bound by duty. Her child was dead. But she would not be. Could not be. Bound by duty to remain until there was another of the Blood to take her role of Abhorsen.
Slogging her way back to the tepid doorway into life, she wept. As Chlorr crossed the First Gate, she realized how fortunate she was not to have encountered anything, for she did not have her sword or bells. But as she thought that, she smelt the reek of Free Magic, and glimpsed the silver white of a Free Magic being. Her heart jumped into her throat, but as it spoke, she relaxed.
"Will you please hurry along, Mistress? You know how I hate to be wet." The familiar voice of Mogget cut through the burble of the water like a pin through silk. Chlorr did not hurry, but approached at the same speed she'd made between the other Gates of Death.

Mogget watched the Abhorsen approach, and noticed a peculiarity in his mistress. She must have gone beyond the Fifth, he reasoned. He did not say anything about her appearance, though he wanted to. He would wait until she was in front of her mirror.

Chlorr gasped as her spirit returned to Life. Ice flaked off of her, leaving her chilled. She wailed in grief for her lost heir, and she moved to wipe the tears from her eyes. When her fingertips reached her cheekbones, her flesh yielded like water, and she felt the faint buzz of magic, as she did when she touched a Charter-sending. Her breath blew out of her mouth and her fingertips probed there. Her breath was warm on her calloused hands, but she didn't feel her lips. Only the slight tingle. Her hands flew up to her forehead, to touch her baptismal Charter-Mark. As her fingers met her brow, she wasn't connected with the Charter. There was no accustomed golden flash. There was just... nothing.
Nothing at all.
She wept for her child, and for herself. Her tears leaked out of her eyes and struck the puddles on the floor, splashing.

Dawn broke, a rosy pink light creeping up the wall surrounding Abhorsen's House. No Dead creatures had found their way through the shattered wards into the realm of Astarael's get. Which was just as well, for the Abhorsen was not paying attention to her surroundings. Holding the still corpse of her deceased child in her right arm, she delved carelessly into books of spells, searching for one that might yet save her daughter. They held nothing – no spell that wouldn't take a moon's preparation or more to cast and control. That was much too long to wait.

Chlorr, holding Sethern, plunged again through the barrier between Life and Death. Chanting Free Magic spells as she ran across the presincts, she screamed out her heartache.

Grief, pain and fury – a sound no necromancer could ignore. Not when carelessly shouted out beyond the Fifth. He smiled, fingered the black-handled perversion of Mosrael, and approached the grieving woman.

"Give up your bells, Abhorsen, and I will give you back your child. It isn't fair, is it, that life should be taken so?"

Chlorr, Abhorsen no more, silently handed to the mage the body of her daughter.