“Professor Phlebas.” Tree nodded to the headmaster. Then he regarded Wragg with a look of utter contempt.
“Glad you could join us, Professor Tree. I wondered if you could enlighten us as to why you were unable to grade this candidate in crucifixion technique?”
“I sure can, Professor Phlebas.” Tree spoke with his characteristic Missouri drawl. “Despite two whole years, in which I spared no effort in teaching and demonstrating the correct procedure for nailing a woman to a cross to this miserable wretch, when it came to the practical exam I ended up wondering why I’d bothered!”
Wragg looked at his feet, as Tree continued mercilessly.
“I sent him to the dungeon to collect the slave Thessela for crucifixion. He returned with Malins. I sent him back, and he returned with Barbaria, who had threatened him with demerits if he didn’t crucify her instead of Thessela. I sent him back again again, and this time he did manage to bring Thessela back, but he was carrying the patibulum instead of her. Apparently she’d told him that she couldn’t carry it herself because she had a cold.”
Tree sat for a moment, with his head in his hands, unable to continue. Eventually he composed himself.
“It took him six attempts to assemble the cross. Six! I mean, how hard can it be? There are two pieces of timber, arranged at right angles to one another….
“By the time he’d got the thing arranged in a rough approximation of a cross shape, Thessela had gone. Basic crucifixion technique – immobilise the subject during preparation of the cross. Oh no, that’s not for Mr Wragg, he’d just left her standing there. To be fair to her, she hadn’t exactly run away, just got bored and wandered off to find something more interesting to do.
“After fifteen minutes of frantic searching, he found her sitting in the quad, being chatted up by a bunch of lads from the fourth year, who had presented her with flowers picked from one of the borders.
“So he waited patiently for her to stop speaking to them, because he was too polite to interrupt her!” Tree slapped himself on the forehead. “’I say, excuse me, Miss Thessela,’ he said, ‘but would it be all right for me to crucify you now?’ The fourth years were literally rolling on the floor, helpless with laughter, especially when she said ‘Just a moment, Wraggie, I’m arranging to help these gentlemen with their homework.’
“Things went from bad to worse. He stood there, shifting from one foot to another, looking anxiously from Thessela to myself, utterly at a loss as to what to do next. The fourth years picked themselves up, and one scowled at Wragg. ‘Leave her alone, you old bully! She told you, she has a cold! You can’t go crucifying people who are suffering from a cold! Besides, you’re sure to catch it yourself, all that screaming spreads a lot of droplets!’ At this point Thessela sneezed, so Wragg said ‘Bless you!’, and then came to tell me there was a problem.
“At this point, Professor Phlebas, I confess that I lost all patience. I marked Wragg’s paper as ungradeable and sent him away. I crucified Thessela myself, aided by some very willing and highly competent fourth years. It is my professional opinion that Wragg is completely unemployable in any capacity that involves crucifixion.”
With one more dirty look at Wragg, Tree disappeared in yet another cloud of purple smoke. The smoke itself appeared to frown at Wragg, before it dispersed into the general fog of purpleness in Professor Phlebas’ study.
Phlebas watched it disperse, then continued, “from what Professor Primus tells me, you were lucky to scrape a D- in flagellation, too. Incidentally, Wragg, how do you spell ‘flagellation’?”
Wragg was rattled by this most unexpected question. “F – L – A – double G…..”
“Idiot!” roared Phlebas. “Two years in the company of the greatest flagellator that the world has ever seen, and you, wretched boy, can’t even spell the word!”
Phlebas glared at Wragg over his purple spectacles. Then he asked the sixty-four thousand dollar question. “I wonder what your father will have to say about this?”
Wragg quaked. He knew the answer perfectly well. Lord Despard Wragg would take a very dim view of it indeed. He had passed his own nail levels with straight A pluses, and the honour of the Wragg name was at stake. Wragg junior had resolved to put as much geography between himself and his father as was humanly possible. Australia seemed an attractive proposition.
“P-please sir!” stammered Wragg. “I was quite good with the weird and frightening beasties? Just ask Professor La Croix?”
Phlebas considered for a moment. The he said, “Premium timber!” A puff of (you guessed it) purple smoke, and there stood Professor Messaline La Croix. On her shoulder sat a squirrel.
The squirrel was red, and clashed most dreadfully with his purple surroundings.
)
You're certainly on a roll with this one Wragg. 
"There see I blend in better already!"
"So who needs help making a cross?"
"A cross not cross hairs Professor Tree, we have been over this already!" 
"I spared no effort in teaching and demonstrating the correct procedure" 
"Immobilise the subject during preparation of the cross. Oh no, that’s not for Mr Wragg, he’d just left her standing there."
"At this point Thessela sneezed, so Wragg said ‘Bless you!’, and then came to tell me there was a problem."
"I marked Wragg’s paper as ungradeable and sent him away."
