The tale begins when Dr. Suzana, under the supervision of Prof. Dr. Taib Siron, created a machine named BS21 which is capable of reading people's minds. The machine would be very much useful for millitary use but would be very deadly if it were to fall in the wrong hands. The most feared incident happened when Cat and his sidekick Kupan stole BS21 from Dr. Suzana's lab. One of the eyewitness who saw the incident was Hashim a security guard at the lab. Another thing that they don't know about the machine is that it is also capable of granting wishes those who use the machine.

Brainscan: Aku dan Topi Ajaib

This time around, the gang - Azlee, Mazlan and Wahid go for a vacation to an island resort. Upon their arrival, they discover that the resort isn't what they had expected it to be. It looked deserted and on the verge of bankruptcy. They decide to help the owner, Mansor to restore the resort and attract more tourists. But, things didn't go well. Disappointed by the situation, they decide to call it quits and leave the resort. However, things go awry when Remy comes into picture offering a salvation on Mansor's business. Noticing something fishy about Remy's plan, Mazlan steps in and unveils Remy's true identity to Mansor. Remy goes mad and abducts Mansor's daughter, Qasidah. Once again, the gang face bigger test in their attempt to rescue Qasidah.