show for Mendel's theory of genetics.
   One of the detectives came forward, his hands in his coat pockets, and said to 
Jennifer, 'Sergeant Clay, ma'am. And this is Detective Clay.'
   Both sergeant and detective were tall and smooth-skinned, with those flat, 
almond-shaped faces and slightly hooked noses that betray Arabian ancestry. They both 
wore shiny metallic mohair suits and black loafers. The only noticeable difference 
between them was that Sergeant Clay had one brown eye and one gray one; while Detective 
Clay's eyes were both brown.
   'Mind if I take a look?' asked Sergeant Clay, and eased open the bedroom door. His 
twin followed him inside. The two uniformed officers waited on the landing, one of them 
assiduously penciling notes in his notebook, the other yawning.
   'Well, they made some kind of a mess,' Sergeant Clay remarked. 'How much did they 
take?'
   That's the odd part about it,' said John from the doorway. 'As far as we can make out, 
they didn't take anything at all. They just broke the place up.'
   Detective Clay crouched down on his haunches, balancing himself with the splayed 
fingers of one hand. His nostrils flared slightly, as if he were trying to distinguish 
some faint and equivocal odour.
   They broke everything,' put in Jennifer. 'There isn't one single item in this room 
that hasn't been torn or damaged or thrown around.'
   Sergeant Clay stepped carefully all around the room, glancing at this, studying that. 
Eventually he said, 'How do you think they got in?'
   'What?' asked John.
   'I said, "How do you think they got in?'"
   John made a face. 'I really have no idea. The garden door has been locked all day, and 
nobody could have come in that way this evening without us seeing them. All of the 
downstairs windows have security bars and locks. And apart from the fanlights in this 
room and Lenny's bedroom down at the end of the corridor and the John across the landing, 
all of the upstairs windows are closed and locked.'
   'Have you looked around the house since this happened?'
   John   nodded.   'I   haven't   checked   every   room downstairs, and I haven't 
checked the cellar, but as soon as we heard the noise we came running straight up here, 
and I really don't see how
   Sergeant Clay leaned sideways, his hands still in his pockets, so that he could see 
out the bedroom door. 'Officer Mulroony,' he said. 'Would you be good enough to search 
the ground floor - cellar, too?'
   The officer stopped scribbling in his notepad, tapped his pencil on the peak of his 
cap in salute, and went downstairs.
   Sergeant Clay said, 'Officer Sabido, would you be good enough to go down to my car and 
bring me my Polos?'
   'Yes, sir.'
   'Your Polos?' asked John. 'What are your Polos?'
   They're little round mints like Life Savers. I have a friend who brings them across 
from England. You can stick the tip of your tongue through the hole in the middle, and 
apart from the fact that I was called away from a double-hot chilli to go and I'm going 
to be breathing it at you every time I ask you a question, they help me to think.'
   John glanced at Jennifer in bewilderment.
   'You'd prefer it if I smoked a pipe and played the violin?' Sergeant Clay asked him 
with perfect politeness.
   At that moment, Detective Clay began to sniff even more deeply, holding his breath for 
long, quivering moments and then exhaling.
   'What's gotten into him?' asked John.
   Sergeant Clay laid a hand on his twin's shoulder and said, 'He's very sensitive to 
different smells, you know what I mean? He can tell you what brand of cigarette you smoke 
just by sniffing your hair. He can tell what spices you've been eating, anything from 
bell peppers to fenugreek, and everything in between. He can tell if you've recently been 
close to animals, and what kind. He can smell something now.'
   Detective Clay carefully reached over and grasped the corner of the ripped-open 
comforter. He hesitated for a moment, still breathing deeply, then suddenly whipped it 
off the bed.
   On the sheet underneath, a huge wet stain was spreading, smelling faintly acrid and 
tinged with yellow at the edges.
   'Oh, my God,' said Jennifer, and clamped her hand over her mouth.
   'I'm sorry ma'am,' said Sergeant Clay gently. 'We often get this kind of vandalism. 
For some of these sickos, breaking into somebody's bedroom is pretty much like rape 
once-removed. You're lucky they didn't do anything worse.'
   'You mean I'm lucky that they only pissed on my marriage-bed, instead of shitting on 
it?' Jennifer demanded, her voice scratchy with shame and fury. Shame - almost as if this 
disgusting desecration were her doing.
   John held her close. 'It's okay, Jenny. We'll get rid of it and start fresh. New bed, 
new sheets, new carpet.'
   'It's not the same,' Jennifer wept. 'It's my marriage-bed. It meant so much.'
   Detective Clay leaned over the bed and kept on sniffing, his eyes closed.
   'One person, or more than one, what do you think?' Sergeant Clay asked him.
   Detective Clay kept his eyes closed and didn't answer, but raised his hand to indicate 
that he was still concentrating.
   'Any alcohol? Unusual foods? Coffee? Tea?' Sergeant Clay asked.
   Still Detective Clay kept on sniffing.
   'Come on, Norman, was it a man or a woman? Or both?' Sergeant Clay turned to John and 
Jennifer and said, 'He can usually tell that, too. It's something to do with the proteins 
in the urine.'
   Quite abruptly, Detective Clay went up to his twin and whispered something in his ear. 
Sergeant Clay blinked, frowned, and said, 'Are you sure?'
   'What is it?' Jennifer wanted to know. 'What can he smell?'
   Sergeant Clay rubbed his chin thoughtfully. 'I don't know, ma'am; I think he's making 
some kind of mistake.'
   'Does he often make mistakes?' asked John.
   Sergeant Clay shook his head. 'Never. Never known him to make a mistake.'
   'So why do you think he's making a mistake this time?'
   'Well, sir, because he says this is urine right enough, and plenty of it. But whoever 
did it must've had a bladder that was five times the usual capacity, and whoever did it 
wasn't human.'
   'You bet they weren't human,' John agreed.
   'No, sir, you don't quite understand me. Whoever did this genuinely wasn't human.'
   John stared at him, baffled. 'You mean an animal did this?'
   Sergeant Clay stared back at him with a concentrated frown. Behind him, his twin 
frowned, too.
   Then what?' John demanded. 'If it wasn't human, and if it wasn't an animal - what?'