〃It is Veritaserum…a Truth Potion so powerful that three drops would have you spilling your innermost secrets for this entire class to hear；〃 said Snape viciously。 〃Now； the use of this potion is controlled by very strict Ministry guidelines。 But unless you watch your step； you might just find that my hand slips〃…he shook the crystal bottle slightly…〃right over your evening pumpkin juice。 And then。 Potter。。。 then we'll find out whether you've been in my office or not。〃
Harry said nothing。 He turned back to his ginger roots once more； picked up his knife； and started slicing them again。 He didn't like the sound of that Truth Potion at all； nor would he put it past Snape to slip him some。 He repressed a shudder at the thought of what might e spilling out of his mouth if Snape did it。。。 quite apart from landing a whole lot of people in trouble…Hermione and Dobby for a start…there were all the other things he was concealing。。。 like the fact that he was in contact with Sirius。。。 and…his insides squirmed at the thought…how he felt about Cho。。。 He tipped his ginger roots into the cauldron too； and wondered whether he ought to take a leaf out of Moody s book and start drinking only from a private hip flask。
There was a knock on the dungeon door。
〃Enter；〃 said Snape in his usual voice。
The class looked around as the door opened。 Professor Karkaroff came in。 Everyone watched him as he walked up toward Snape's desk。 He was twisting his finger around his goatee and looking agitated。
〃We need to talk；〃 said Karkaroff abruptly when he had reached Snape。 He seemed so determined that nobody should hear what he was saying that he was barely opening his lips； it was as though he were a rather poor ventriloquist。 Harry kept his eyes on his ginger roots； listening hard。
〃I'll talk to you after my lesson； Karkaroff；〃 Snape muttered； but Karkaroff interrupted him。
〃I want to talk now； while you can't slip off； Severus。 You've been avoiding me。〃
〃After the lesson；〃 Snape snapped。
Under the pretext of holding up a measuring cup to see if he'd poured out enough armadillo bile； Harry sneaked a sidelong glance at the pair of them。 Karkaroff looked extremely worried； and Snape looked angry。
Karkaroff hovered behind Snape's desk for the rest of the double period。 He seemed intent on preventing Snape from slipping away at the end of class。 Keen to hear what Karkaroff wanted to say； Harry deliberately knocked over his bottle of armadillo bile with two minutes to go to the bell； which gave him an excuse to duck down behind his cauldron and mop up while the rest of the class moved noisily toward the door。
〃What's so urgent？〃 he heard Snape hiss at Karkaroff。
〃This；〃 said Karkaroff； and Harry； peering around the edge of his cauldron； saw Karkaroff pull up the left…hand sleeve of his robe and show Snape something on his inner forearm。
〃Well？〃 said Karkaroff； still making every effort not to move his lips。 〃Do you see？ It's never been this clear； never since…〃
〃Put it away！〃 snarled Snape； his black eyes sweeping the classroom。
〃But you must have noticed…〃 Karkaroff began in an agitated voice。
〃We can talk later； Karkaroff！〃 spat Snape。 〃Potter！ What are you doing？〃
〃Clearing up my armadillo bile； Professor；〃 said Harry innocently； straightening up and showing Snape the sodden rag he was holding。
Karkaroff turned on his heel and strode out of the dungeon。 He looked both worried and angry。 Not wanting to remain alone with an exceptionally angry Snape； Harry threw his books and ingredients back into his bag and left at top speed to tell Ron and Hermione what he had just witnessed。
They left the castle at noon the next day to find a weak silver sun shining down upon the grounds。 The weather was milder than it had been all year； and by the time they arrived in Hogsmeade； all three of them had taken off their cloaks and thrown them over their shoulders。 The food Sirius had told them to bring was in Harry's bag； they had sneaked a dozen chicken legs； a loaf of bread； and a flask of pumpkin juice from the lunch table。
They went into Gladrags Wizardwear to buy a present for Dobby； where they had fun selecting the most lurid socks they could find； including a pair patterned with flashing gold and silver stars； and another that screamed loudly when they became too smelly。 Then； at half past one； they made their way up the High Street； past Dervish and Banges； and out toward the edge of the village。
Harry had never been in this direction before。 The winding lane was leading them out into the wild countryside around Hogsmeade。 The cottages were fewer here； and their gardens larger； they were walking toward the foot of the mountain in whose shadow Hogsmeade lay。 Then they turned a corner and saw a stile at the end of the lane。 Waiting for them； its front paws on the topmost bar； was a very large； shaggy black dog； which was carrying some newspapers in its mouth and looking very familiar。。。
〃Hello； Sirius；〃 said Harry when they had reached him。
The black dog sniffed Harry's bag eagerly； wagged its tail once； then turned and began to trot away from them across the scrubby patch of ground that rose to meet the rocky foot of the mountain。 Harry； Ron； and Hermione climbed over the stile and followed。
Sirius led them to the very foot of the mountain； where the ground was covered with boulders and rocks。 It was easy for him； with his four paws； but Harry； Ron； and Hermione were soon out of breath。 They followed Sirius higher； up onto the mountain itself。 For nearly half an hour they climbed a steep； winding； and stony path； following Sirius's wagging tail； sweating in the sun； the shoulder straps of Harry's bag cutting into his shoulders。
Then； at last； Sirius slipped out of sight； and when they reached the place where he had vanished； they saw a narrow fissure in the rock。 They squeezed into it and found themselves in a cool； dimly lit cave。 Tethered at the end of it； one end of his rope around a large rock； was Buckbeak the hippogriff。 Half gray horse； half giant eagle； Buckbeak's fierce orange eye flashed at the sight of them。 All three of them bowed low to him； and after regarding them imperiously for a moment； Buckbeak bent his scaly front knees and allowed Hermione to rush forward and stroke his feathery neck。 Harry； however； was looking at the black dog； which had just turned into his godfather。
Sirius was wearing ragged gray robes； the same ones he had been wearing when he had left Azkaban。 His black hair was longer than it had been when he had appeared in the fire； and it was untidy and matted once more。 He looked very thin。
〃Chicken！〃 he said hoarsely after removing the old Daily Prophets from his mouth and throwing them down onto the cave floor。
Harry pulled open his bag and handed over the bundle of chicken legs and bread。
〃Thanks；〃 said Sirius； opening it； grabbing a drumstick； sitting down on the cave floor； and tearing off a large chunk with his teeth。 〃I've been living off rats mostly。 Can't steal too much food from Hogsmeade； I'd draw attention to myself。〃
He grinned up at Harry； but Harry returned the grin only reluctantly。
〃What're you doing here； Sirius？〃 he said。
〃Fulfilling my duty as godfather；〃 said Sirius； gnawing on the chicken bone in a very doglike way。 〃Don't worry about it； I'm pretending to be a lovable stray。〃
He was still grinning； but seeing the anxiety in Harrys face； said more seriously； 〃I want to be on the spot。 Your last letter。。。 well； let's just say things are getting fishier。 I've been stealing the paper every time someone throws one out； and by the looks of things； I'm not the only one who's getting worried。〃
He nodded at the yellowing Daily Prophets on the cave floor； and Ron picked them up and unfolded them。 Harry； however； continued to stare at Sirius。
〃What if they catch you？ What if you're seen？〃
〃You three and Dumbledore are the only ones around here who know I'm an Animagus；〃 said Sirius； shrugging； and continuing to devour the chicken leg。
Ron nudged Harry and passed him the Daily Prophets。 There were two： The first bore the headline Mystery Illness ofBartemius Crouch； the second； Minis