Bomb

He opened the back of the unit with great care. It looked like there was a pretzel of twisted, colourful wires inside.
"What do you see?" crackled the voice through his radio.
"More than expected," he replied.
"Ok." a pause. "Have you got a green wire?"
"There's light green; dark green; green and white; and green and yellow."
"Just a second."
Time was running out and  'just a second' never means just a second.
Two minutes passed.
"We think it's the dark green."
"You think?"
A bead of sweat ran down his forehead, stinging his eye.
"We're 99% sure."
He sighed and positioned his cutters around the wire. He paused, thinking about his wife and daughter - would he ever see them again?
He couldn't look as he clipped the wire. SNIP! Nothing.
His radio crackled.
"Are you still there?"
He didn't answer. He was shaking, the adrenaline coursing through his body.
"Can you hear me?"
This time he answered. "Yes," he croaked.
"Whatever you do, don't cut the green wi..."