The moment she opened the door, Natasha Romanov knew something was different. There was an energy in the apartment that hadn't been there earlier, and it prickled on her skin like electricity.
Natasha pulled the small pistol from the holster at her hip and made her way through the dark. Senses heightened, she slunk noiselessly between rooms, but found them all clear. The prickling feeling remained, however, and once the lights were on she knew why.
The room, and the whole apartment, was sparse. The building was brand new; built on the Avengers campus to house the eclectic collection of recruits and staff that made up Earth's Mightiest Heroes. She had been offered a larger suite after the facility had been built but had turned it down. She'd had no use for the space. Even now, aside from the clothes in her closet, her toiletries, and a few mostly-empty takeout containers in the fridge, the apartment looked exactly as it had when she had moved in.
It was because of this that she immediately noticed the postcard on the coffee table in the simple yet tasteful living room. The bright blues and greens of the tropical landscape on the card were a stark contrast to the muted neutrals in the room. Natasha stared at the card, not entirely sure what to make of it. In her heart, she knew who it was from and why it was there.
Natasha approached the card as though it were about to detonate. Despite years of training and conditioning designed to make her nerves as hard as steel, she noticed her hand shaking as she reached for it.
It had been nearly four months since Ultron had been destroyed. And the Hulk taken off in a Quinjet, Natasha thought darkly. She understood why he'd left, but the emptiness she'd felt at his betrayal hadn't healed. It was a feeling she was not used to, and did not like. Through her time in Russia, and then later at SHIELD, her work had been her life. Becoming friends with Clint Barton was the closest she'd ever come to an emotional attachment, but even that came with a certain level of professional distance. Ever since she'd fallen through the floor of the Helicarrier and watched Bruce Banner morph from the quiet, unassuming doctor to the enormous mass of muscle and rage that was the Hulk, they'd shared a connection.
Natasha had seen firsthand the struggle Bruce went through when he became the Hulk, and saw how much it took out of him when the Hulk left. He'd learned to control it, to a degree; he could decide when he changed, and with the help of her lullaby, he could ease out of it. She knew how hard it was when he saw the devastation he had caused, and seeing his pain sent pangs straight to her heart. She didn't blame him for wanting to go somewhere beautiful and calm.
The photo on the postcard was generic, as far as tropical paradises went. Clear blue-green water and cloudless blue sky broken only by a perfect row of vibrant green palm trees. A reddish shack with a thatched roof built upon stilts rose out of the water. It was perfectly idyllic. Natasha hated it, and she hated Bruce. She was supposed to be there with him, not stuck dealing with a semi-omnipotent android and a emotionally-damaged psychic.
She flipped over the card, not knowing what to expect. Was it an apology? An explanation? Or just a note saying he was gone for good and to not bother looking for him? As the last possibility crossed her mind, Natasha felt her eyes starting to water. Despite how angry she was that he had left her, she missed him.
Natasha stared at the back of the card in confusion before turning it over and inspecting it again. There was only one line on the postcard, written in what she recognized instantly as Bruce's untidy scrawl: "I tried running with it, but ended up running away." It was almost an apology, Natasha thought. The anger she felt came back to the surface, and she threw the card blindly across the room. The door to the apartment slammed behind her, and the postcard fluttered silently to the floor.