Peter Grodin was the first to realize something was happening.

The young man had been fiddling with a few modifications they were always making to one of the control pads – trying to make the Ancient's technology a little more compatible to their own computers that they'd brought with them – when suddenly the gate began to dial. Unlike the gate back home, this one dialed fast, and by the time he'd hit the alarm button to alert the others, the gate was already swooshing open, and there was already a very staticky radio transmission coming through.

The young man was so shocked by the sudden contact, he almost missed the first loop of the transmission.

"'...Stargate Command, we're sending supplies and a traveler through... if you have a shield, lower it please. Repeat; this is Stargate Command, we are sending a traveler through the gate, please lower any shielding you might have...'"

"Peter?"

Elizabeth Weir came over, alerted by the alarm, and Grodin looked up at her.

"It's Earth. They're sending someone through with supplies..."

Weir looked at him in surprise, and then at the gate, which was shimmering behind the protective forcefield.

"You're sure it's Earth?"

"They're sending a transponder code," he confirmed, looking over as Major John Sheppard arrived on the scene with a small security force. "It's SG-2's code. No one could know about our codes but them."

"Lower the shield." Weir commanded, turning to look at the Stargate once more.

Only a moment after the shielding went down, a single form emerged from the Stargate, leaping through. Weir had an impression of someone young, almost definitely female and lithe – and bristling with weaponry. There was a pause as the person looked around and stepped to the side, and then a pallet of what had to be supplies emerged from the gate behind her. And then another almost immediately after that.

Weir felt a surge of excitement and relief – they'd been getting seriously low on some supplies – and had just started to take a step towards the stairs that led down to the floor of the gating area when something completely unexpected and unprecedented happened.

From out of nowhere, a beam of energy struck the newcomer, engulfing her in a hazy blue light. As Weir watched, there was a cry of surprised pain, and the newcomer crumpled to the floor, writhing in obvious pain.

"What the hell is that?" Sheppard asked, alarmed.

"No clue!" Peter said, just as shocked as everyone else at the sudden attack by the city on one of their own.

"Turn it off!"

"I don't even know where it's coming from..." He was looking at his circuit board, dumbstruck.

"It's killing her!" Weir shouted. "Turn it off!"

Even as the newcomer struggled with whatever was happening to her, there were more supplies coming in, oblivious to the fact that the messenger was being bombarded.

"I'm trying!"

Sheppard pulled his pistol out of his holster, raised it and pointed it at the device on the wall the beam was emanating from and fired into it. Six times in rapid succession. The beam shut off, and the agonized writhing stopped. The newcomer lay still, almost lifeless, and the Stargate shut down. All of them stared in shock.

"What the hell was that?" Sheppard asked, being the first to recover. He was already on his way down the stairs when Grodin answered.

"I don't have a clue. It came out of nowhere, and I've never seen it do that before..." He looked at Weir, who was coming out of her own daze at such a violent greeting. Elizabeth shook her head; she didn't know.

"Did we get a message off to Earth?" She asked, hopefully. She hadn't even thought of it, but hopefully someone else had.

Grodin shook his head, ruefully. He'd been too shocked by the sudden turn of events to do more than try to find out what was happening. He hadn't even give thought to sending a reply.

"I'm sorry..."

"What happened?"

They all turned at the sound of a new voice, and Rodney McKay walked through the door, obviously just come from eating lunch, since he was still holding his sandwich.

"We need a medical team!" Sheppard called, and McKay looked down at him. His eyes widened when he saw the copious amount of supplies suddenly materialized from nowhere.

"Where did those come from?"

"Earth." Weir said, moving to the stairs and down them, followed by Rodney. In the background they could hear Grodin calling for a medical team. "They sent someone, but something happened and this weird beam... how is she, Major?" Weir interrupted herself as she and McKay came close to where Sheppard was kneeling next to the downed form, his hand resting gently on her neck, searching for a pulse.

"She's alive, but unconscious."

"Who is she?" McKay asked, taking a bite out of his sandwich.

Sheppard gave him a reproachful look, but ran his hands along the woman's neck, following the dog tag chain until he found her tags. Moving carefully to avoid injuring her further, he leaned over to read them.

"Melony Mitchell." He looked at her insignia on her uniform. "Colonel Melony Mitchell."

"What? Really?"

McKay dropped down next to Sheppard, and leaned close to read the tags himself.

"Wow! What's she doing here?"

"You know her?" Sheppard asked, before Weir could. Obviously, he knew something they didn't. Big shock there.

Rodney was looking at the still form in amazement.

"Yes. I mean, no. I don't know her. But I know who she is. You guys-"

"What's this?"

They all looked over at the arrival of Carson Beckett, who was rushing up with a first aid kit in his hand and a small army of medics right behind him with a gurney.

"She's been hit with some beam, Carson," Weir told him. "I've never seen anything like it."

Beckett dropped next to Sheppard and started his examination.

"Is she going to be all right?" McKay asked, still holding the sandwich, although it was obvious it was the last thing on his mind just then. Which was, in itself, an oddity.

"I just got here," the Doctor said, pulling out his stethoscope. "Give me a chance to find out what's wrong with her."