Saif is seen in a never-before avatar, in the role of a naga sadhu.
In the first chapter of the trailer, which is titled The Hunt, Saif is being potrayed as wrathful and dangerous assassin.
"Aadmi ke paida hote hi, kaal apne bhainse pe baith ke chal padhta hai use vaapis laane. Aadmi ki jindagi utni, jitna samay laga bhainse ko us tak pohonchne," Saif can be heard saying in the intense voice in the trailer.
With a red teeka on his forehead and dark kohl-rimmed eyes, his hair tied in a bun and face smeared with ash, Saif cuts an imposing picture, and social media is enthralled.
Sonakshi Sinha makes a cameo in the film, and her voiceover can be heard in the trailer, too.
Reacting to the trailer, one user compared Saif's look to Johnny Depp's Jack Sparrow in the Pirates Of The Caribbean series.
Most others, however, were upbeat about film's first look. "Impressive. Eagerly waiting for it," one user commented.
Laal Kaptaan is directed by NH10 maker Navdeep Singh and is scheduled to release on October 18.