Megastar Mammootty, who seems to be on a roll with his back-to-back hits this year — ‘Bheeshma Parvam’ and ‘CBI 5: The Brain’ — is coming to score a hattrick with yet another crime thriller. This time, he has moved over to the dark side and appears without the pomp and glory of his stardom. Debutant director Ratheena PT, by the looks of it, has built the perfect launch vehicle that could catapult her right to the forefront of the radically evolving Malayalam film industry, at least when it comes to movies. ‘Puzhu’ (Worm) will start crawling at midnight on SonyLiv. But, with SonyLiv being the streaming platform of surprises,…