Disclaimer: I don't own SGA, the characters etc.
She feels alive. Strong. Like she can take on an army. Like she wants to take on an army. "You feeling okay?" Ford asks. There's something in the way that he says it.
"What did you do."
"I'm just showing you what you're missing."
"Ford," she does not know what is happening but somehow she has her arm against Ford's throat as she backs him into the wall. "What. Did. You. Do."
"Looks like it worked," he's grinning. "What'd I tell you, feels amazing, doesn't it?"
Teyla releases him. "We came here for a job. We came here to put an end to the Wraith drug and you-"
"You don't get it," Ford smiles widely. "We're here to take down the Wraith Organization. Not the drug. This is the answer."
"What are you talking about?"
"Think about it. You feel stronger, don't you? It gets better."
"Ford—"
"It's perfect for us, for our job."
"It has clearly clouded your mind and your judgment."
"No, it's made me see things clearly." His smile has fallen. "You'll see, eventually you'll see."
She is the one who tells Ronon Dex. She knows that he will pass the information on to Sheppard. "Ford is dead. He overdosed on the Wraith drug."
And still, after her brief meeting with Dex, she puts the needle into her skin. Ford was right, after all. His downfall was not knowing how to control it.