What if the injection Linda had given Boyd was meant for Grace? Series 8 Episode 'Endgame'.
His heart was already beating faster than it should have been. His heart, however, skipped a beat when his eyes caught a glimpse of what was contained in the plastic box. At first, he had no idea what he was meant to do with it nor what was contained inside, but terrible thoughts began to form in his mind. He cast a raised look towards Linda, expecting her to react. She gave him nothing except the acknowledgement that he knew what it was.
This was all another part of her game, another move closer to her Endgame. Following her instructions, Boyd reached his destination. Flashbacks quickly appeared. This was the last time he saw his son and he struggled to contain his composure. Every move he made, he knew Linda was watching. He couldn't let her use his emotions against him, he had to conceal them. Linda, however, already had the upper hand. As much as he hated Linda, he had to obey her rules. He had to play along, otherwise, he could risk losing the one person close to him. Grace.
The anger flowed through his veins, not just at Linda but towards Jackie too. She'd betrayed his trust, betrayed the team's trust. Her connection with Linda had allowed Linda to manipulate the situation to her own satisfaction. Through Jackie, Linda was able to use Grace as a pawn in her game, bait to draw Boyd deeper into her own warped mind. While the anger he felt towards Linda and Jackie was palpable, the anger he felt towards himself was overwhelming. He'd let Linda fool him and played right into her hand. Linda now had full control of the situation, the one thing he'd promised Grace he'd never do. To play the game, but stay in control. Now that was gone, he had no leverage, nothing he could use against Linda. She was one step ahead of him and the team as usual. Al Boyd could do now was to allow the game to unfold, let Linda show him what her Endgame was.
The empty warehouse echoed with his footsteps, his phone gripped in his hand as he walked cautiously through the abandon corridors. Hesitantly he followed the direction Linda was taking him. Soon, he found himself in a spacious unit. There was nothing in there apart from bits of rubbish and broken furniture. The silence was soon disturbed by a muffled sound. Boyd looked around to see where the sound was coming from when he saw an adjoining room. The muffled noises continued and he carefully walked towards the open doorway. The muffled sounds became clearer and as his eyes laid on the scene in front him, his heart dropped to the pit of his stomach. There bound and gagged into a wheelchair was Grace. Boyd felt himself run towards her, when Linda's voice interrupted and stopped him in his tracks.
"Uh, uh. I need you to stay where you are, Peter"
Boyd stood still and looked around to see where her voice was coming from. Up in the corner of the room was a small webcam. So that's where she was observing from, he said to himself.
"What do you want me to do?" his voice was hoarse. Boyd expected there to be a pause after his question, but Linda's voice was immediately heard.
"The syringe I gave you, take it out."