What goes on in a teenager's mind can be quite mysterious to adults around him. A high-school student in China recently gave his parents a scare when he disappeared from home and all his parents found was a very strange note left by his PC.

When 17-year old Yang Bin (named changed for the report) did not show up at school, his mother received a phone call from his teacher. After the worried mom and relatives could not find him anywhere, she contacted the local police.

She told police officer Lu that her son went to the bus station as usual to take the bus to school. Office Lu surmised that Yang Bin must have taken another bus. But why, and where did he go?

That night, the mother found a cryptic note by her son's PC. The note was full of strange symbols and squiggles. At the end of the note, it was written, "Want to know where I am? Solve this puzzle."

Officer Lu now reasonably concluded that Yang Bin was not kidnapped. He also learned that the teenager was a good student who excelled in chemistry and enjoyed reading novels, such as Sherlock Holmes. Unfortunately, he could not figure out the unusual note and eventually gave it to radio enthusiast Tang Xue Fung, who immediately recognized the note was written in Morse codes.

In case you didn't know, Morse code is a form of transmitting text information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment. The most well-known distress signal is SOS or three dots, three dashes and three dots, internationally recognized by treaty. (en.wikipedia.org)

Tang and his friends were able to decipher the note. The key to the puzzling note was actually using a combination of the Morse-code alphabet and the periodic table in chemistry. The message turned out to be pretty simple and not scary.

It said, "Mom and Dad, don't worry, I will come back. Please notify the school. There's no need to look for me. I just want to have some fun. I'm tired of your lecturing me and need to go away for a few days."

Four days later, Yang Bin returned by himself and showed up at school. Hopefully, both he and his parents will find better ways to communicate from now on.