When Arren climbed out of the sewers, he was already aware that what he would be seeing was an abandoned playground, but he still chose to be cautious. Only after he made sure he couldn't hear any sounds in his vicinity did he open the lid and reveal himself.
As he sat on the ground, Arren exhaled heavily, but there was now a slight sense of relief within him. He allowed himself to relax for a while; after all, he was too tense earlier, and he deserved these seconds of calm.
Not even a minute later, he had already composed himself, putting the almost worn-off lid back in its place. He didn't dare linger in the place, and he quickly left the area.
Although he had the assurance that even if his disappearance was discovered, they would not immediately know where he was. At least, their best course of action was to find Arren in the mansion first, as they didn't know that he would have knowledge of any hidden paths there.