Tricky Verbs with Gerunds and Infinitives. Listening Gap Fill

Detective Marcus Webb had tried the door, but it was locked. He tried , but there was no response. He could not afford to waste time. He needed to find a way in. Then he remembered a man bending down in front of this very door a few days ago. Maybe that was a clue. Marcus bent down to investigate, and there, in a small crack, he saw the end of a tiny key. He pulled it out and unlocked the door.
Marcus knew he should remember the key back later so that nobody would realise that he had used it. The room inside was messy. Whoever had been here last had forgotten . Papers were scattered everywhere, and a chair had fallen over. Marcus stepped in quietly, making sure not to make a sound.
He looked around, and then he saw it. The mark.
He would never forget that mark for the first time, all those years ago. It was the same mark from a case at the beginning of his career. Back then, he did not realize that the case would become so scandalous, or that the suspect would become one of the most notorious criminals in history. And now, here it was again. A white circle. This was no coincidence.
Suddenly, Marcus heard voices. He stopped to the conversation, but they must have sensed someone was listening, because they quickly stopped . He decided to move closer. He needed to find out what they were saying.
He moved down the hallway and slowly opened the door to the next room. He instantly regretted it. The room was full of people, and they all turned to look at him. One of them, a tall man in a dark coat, stepped forward.
“I regret you, Detective, that you are quite mistaken if you think you can stop us,” the man said with a cold smile.
Marcus stayed calm. He had to. He must not let them he was nervous. He needed to stop them. He remembered his breathing steady as he faced the group.
The tall man laughed and gestured to his friends. “Please make sure that our guest leaves the property safely,” he ordered. Two of the men moved toward Marcus.

Marcus did not resist. He knew he had to think of another plan. As they pushed him outside, it started . The tall man began to walk away, and Marcus started him at a distance. He had to be careful not to be seen. He could not let them get away this time.
The rain got heavier, and Marcus began to feel cold, but he would not stop. He had promised himself years ago that he would catch this criminal, and he wasn’t going to give up now. He had forgotten how many times he had tried to solve this case, but this time, he would not fail. He had to find out the truth, no matter what.