This detail is not doled out in linear fashion. Khufiya begins with a birthday soiree in Bangladesh, where an attractive woman brings a gift for Brigadier Saqlain Mirza (Shataf Figar) of the Bangladesh military, believed to be in cahoots with Pakistani intelligence. The gift is actually a lethal weapon, but the woman has been betrayed, and she is the one killed (with a fork stabbed into her jugular, perhaps a nod to Julius Caesar's murder?). The woman is Heena Rahman aka Octopus, a protege of Krishna. We soon enter a flashback in which Rahman proactively approaches Krishna with an offer to spy for her. Rahman is played by sensational Bangladeshi actress Azmeri Haque Badhon, whose innate magnetism makes it easy to digest the chemistry she develops with Tabu's character and the emotional turmoil caused by her assassination. Long after her character is off the screen, you feel her impact.
Bound by orders from her superior (Ashish Vidyarthi, in a rare non-mugging part) and driven by personal angst, Krishna sets out to catch the mole responsible for Heena's death. The obvious suspect is staffer Ravi Mohan (Ali Fazal) who seems to enjoy a lifestyle exceeding his official income. Ravi is rather easily recorded copying office secrets (literally, on a photocopy machine. It seems a little too quaint, but the narrative is set in the pre-millennium years, when USB drives and even CD burners were not mainstream technology). To figure out who is pulling his strings and how the information is transmitted, they set up an elaborate surveillance network covering Ravi's home as well. Thus we are introduced to his wife Charu (Wamiqa Gabbi, of Godha and Jubilee fame) and mother Lalita (Navnindra Behl). Charu is a doting spouse and mother...who, when alone, rolls her own joints and shakes a sexy hip to hippie-era Bollywood ditties. Lalita spends time with an Osho-inspired spiritual guru Yaara-ji (Indian Ocean / Aisi Taisi Democracy's Rahul Ram). When KM's team sets out to apprehend Ravi, things go very wrong; she has to start all over to catch a traitor and avenge the death of her lover.
From a bare outline this must sound all bog standard for the spy genre. But, at least when it's not wavering, there is an emotional core that's more John le Carré than Robert Ludlum. From what I hear, the script (by VB and Rohan Narula) changed the lead of Amar Bhushan's source novel to a woman and a queer. It takes the narrative to a more interesting personal, even romantic space. KM's equation with Heena has her deeply hurting by the latter's death, more so since she cannot discuss it with anyone (the ex-husband seems quite understanding, but I guess there are some things hard to share with a spouse). When Ravi's wife, after having been abandoned by him in escape, reaches out to Krishna to track him and reunite with her son, Krishna understands the perspective of a mother deprived of her child's love (Of course, it helps that this ties in with her own agenda). Even Ali Fazal's traitor is given some dimension - Ravi is a loving family man, but when Charu catches up with him again, he has to worry about her true motives and the risk to his own survival.
So far so good, but Khufiya's script fumbles badly in the consistency department. Almost as if Bhardwaj is afraid of audiences not being gripped by a serious drama, he bungs in jokes and farcical elements that break the immersion. The aforementioned fork stabbing is more Grand Guignol than anything else. When Charu tracks down Ravi in hiding, it would have been interesting to see how her mission tangled with her emotional involvement with the family, but this is jettisoned in favor of cheap jokes like when her mother in law pooh-poohs Ravi's security concerns describing her as a godsend "free maid". A later scene where a target is lured in with the idea of giving him a doped mutton dish and the other members at the table keep giving excuses about why they are not consuming it views like a particularly bad scene from a Jeffrey Archer novel.
Still, I was carried enough by the good stuff (Farhad Ahmed Dehlvi's cinematography is classy cool) to sit through the not-inconsiderable 157 min runtime in one go without feeling too distressed, which is more than I could say about some of VB's other films in the past few years, or the ridiculously overrated Raazi from Meghana Gulzar. Your mileage may greatly vary.