The Hogsmeade weekend came around on a bright cold Saturday, and the relief of being outside the castle was immediate and slightly drunk-feeling, the way fresh air always felt after a concentrated stretch of stone corridors and lesson schedules.
Ginny joined the group. The five of them walked down to Hogsmeade in a carriage, leaves in the gutters and frost at the edges of things, and went directly to the Three Broomsticks for butterbeers and a table near the back where they could actually talk.
Hermione was still turning over the Ministry letter. "Dumbledore is right that we can't do the same thing twice. The first time, the context made it plausible — no one was watching. If they send someone specifically to watch—"
"Then we make sure there's nothing worth watching," Kevin said. "Normal school. Normal classes. Normal study group for motivated students." He set down his butterbeer. "Actually, the D.A. being visible helps us. It's harder to characterize a large, multi-house Defense study group as a subversive operation when the alternative interpretation is just students preparing for OWLs."
Hermione considered this, found it sound, and nodded.
Harry reached across the table for the cloth bag Kevin had produced from his coat. "What's this?"
"New prototype badges. These are for you to distribute." Kevin pulled out the one with H engraved on the back. "Yours. Give out the rest to whoever you trust most as point contacts."
Harry tipped the bag out. A dozen badges, each with a small engraving on the reverse.
"These are different from the first batch," Hermione said, picking one up. It was warm in her palm in a way the earlier versions hadn't been.
"Blood-bond anchor," Kevin said. "Dumbledore suggested it. Instead of the badge filtering for distress, it reads the bearer's own physiological state — heart rate, magical signature, adrenal response. A real attack feels different in the body from sparring, and the badge knows the difference." He looked at Harry. "They also track location when a signal is sent. Whoever holds the H badge can tell roughly where any activated badge is, and vice versa."
"How do you bind it?" Ginny asked.
"First drop of your blood activates it to you. After that, only you get the full network access. An enemy who picked one up would just have an ornamental badge."
Ron looked at the badge in his hand. "Is there a less—"
Kevin slid a small dagger and a vial of powder across the table.
"Oh, come on," Ron said.
"The powder stops the bleeding immediately."
Ron grimaced. He looked around the table. Everyone had already picked up their own badge and was waiting with the specific patience of people who had decided they were going to do this and were ready to watch Ron do it first.
He picked up the dagger. Set the badge on the table. Positioned the blade against his fingertip with the focused preparation of someone going in carefully and doing it right the first time.
He went in carefully and did it somewhat deeper than right.
"BLOODY HELL—"
The blood came freely. Ron grabbed for the powder vial with his other hand. Harry knocked it toward him. Ron got it open, poured it on the cut, and the bleeding stopped with the clean finality of a switched-off tap.
Kevin was staring at the badge.
The badge on the table had not received a drop.
Every drop had gone directly to the table, to Ron's robes, and to the general vicinity of everything except the small object sitting three inches from Ron's right hand that was the entire point of the exercise.
Kevin looked up at Ron. Ron looked at Kevin.
Ron, still pressing the powdered hand to his robes, very slowly reached over, pressed the unwounded fingertip of his other hand to his badge, and bled the correct amount from a fresh, carefully controlled nick.
The badge lit up.
"Right," Ron said.
Kevin picked up his own badge. His.