Batgirl, clad in her iconic black and yellow suit, swiftly moves around the room, checking the equipment and safety measures. Her stern expression reflects her underlying worry for Wanda.

Wanda, on the other hand, tries to remain calm. She is inside the tank, her heart pounding in her chest. Her eyes dart around the room, looking for any signs of danger.

Batgirl leans towards the glass tank, her eyes meeting Wanda's. She offers an encouraging smile, trying to ease Wanda's nerves.

"Remember, Wanda, it's all about control. Just focus on your breathing," Batgirl advises, her voice steady and reassuring.

Wanda takes a deep breath, her eyes closing momentarily. She nods, indicating she's ready to start the challenge.

Batgirl hits the start button on a nearby console. Immediately, the tank starts filling up with water, the level slowly rising.

Wanda's eyes widen as the water begins to engulf her, but she forces herself to remain calm, focusing on her breathing as Batgirl had advised.

Batgirl watches intently, her fingers tapping nervously on the console. She keeps an eye on the timer, ready to intervene if necessary.

Wanda is submerged fully now. She holds her breath, her lungs burning. Her eyes meet Batgirl's, conveying her determination.

Batgirl gives Wanda an approving nod, her confidence in Wanda evident. Yet, her hand hovers over the emergency stop button, just in case.

Wanda fights the urge to gasp for air. She can feel her lungs screaming for oxygen. But she doesn't give in, not yet.

Batgirl watches the timer tick away. It's been over a minute now. She can see Wanda struggling, but she doesn't intervene yet.

Wanda's vision begins to blur. She knows she can't hold her breath much longer. But she doesn't want to give up, not when she's come this far.

Batgirl can see Wanda's struggle. She's about to hit the stop button when Wanda shakes her head, indicating she wants to continue.

Wanda pushes herself further, her body shaking from the lack of oxygen. She knows she has to end this soon, but she wants to push her limits.

Batgirl watches anxiously as Wanda continues to fight. She knows how determined Wanda can be, but she also knows the dangers of pushing too far.

Finally, Wanda gives the signal. Batgirl doesn't hesitate. She hits the stop button, and the water starts draining from the tank.

Gasping for breath, Wanda emerges from the tank. She's exhausted but victorious, having proven her lung capacity in an intense challenge.

Batgirl rushes to Wanda's side, helping her out of the tank. "You did great, Wanda. I'm proud of you," she says, a smile on her face.

Wanda smiles back, still panting. "Thanks, Batgirl. That was... intense." She takes a moment to catch her breath before adding, "But I did it."

"Yes, you did," Batgirl agrees, her pride in Wanda evident. "And you proved that you can handle pressure, even in the most demanding situations."

Wanda nods, a new sense of confidence filling her. She knows she has a long way to go, but this challenge was a step in the right direction.

As they leave the underground lair, Batgirl glances back at the now empty tank. "Next challenge, Wanda?" she teases, a smile on her face.

Wanda chuckles, shaking her head. "Not tonight, Batgirl. But I'll be ready for the next one." The two women exit the lair, their friendship stronger than ever.

As they disappear into the night, the underground lair returns to silence, the echo of their laughter the only reminder of the breathless challenge that took place.