Who is Behind Me?

On Sunday, Adti and siwi went to the park to play, where we studied, played, and saw people making cotton candy. Siwi said "do you know what's the scariest thing?" Then adti answered  "what?" Then came Mark and Cassy Adti's startling "dor" was greeted with bursts of laughter from the people around her seeing Adti shocked. 

Mark asked siwi if they were free today, then siwi answered that today they had done the assignments that Mr. Yaj had done before playing. Cassy invited Mark Siwi to go to the big tree at the back of the park because Adti's sandals were accidentally thrown far back while playing, which in the end was agreed. 

After going to the back of the garden, the four of them were amazed to see this tree was very big. They also forgot their original intention of taking sandals and running around behind the park. Cassy suddenly shouted  "aaaa" then everyone came "Cas what's wrong with you" then cassy answered that she was joking and then they were immediately annoyed to see Cassy. 

Mark then asked where Adti's sandals were because he hadn't found anything there since he was playing. Then he was answered by a woman's voice, "I." Suddenly everyone looked for the woman's voice but couldn't find it, then they were greeted by giggling from the woman and said, "Do you want me to give it back?" Accompanied by the giggling of the disembodied woman. They all scattered and ran out to that place. 

The security guard at the park was shocked to see the teenager coming from the big tree and the security guard said a spell that the teenager did not understand. The students asked for help to open the door, then they convinced the security guard that they weren't ghosts then the security guard said "wait a moment longer" and at that time the security guard told us to pray together in our hearts. 

After the security guard said the mantra we were able to get out from behind the park, then the security guard reminded us never to play behind the park. Mark asked why the security guard took so long to open the door for them. The man was silent and said, fortunately I came here on time, otherwise he couldn't have been saved. Then siwi asked who the security guard meant, then the security guard pointed at Adti and said, "After you come home, quickly take a shower from here because behind you it's very scary," then we were thrown out without a complete explanation by the security guard. 

They were confused and continued to talk about the strangeness that had happened, Adti also explained that he had not done anything strange there, then they went home. When Cassy was about to open the gate of her house, "hihihi" said a disembodied female voice, Cassy screamed.