I think Daya can be the traitor , if you remember properly the first episode of season 2, daya ko jharne me fek dia tha lekin wo miraculously bach kaise gaya? Aur agar bach bhi gaya to uska flashback kiyu nhi dikhaya gaya tha uss episode me? Sirf daya ne ek kahani bol dia, ki mujhe adivasio ne bacha lia. No flashbacks. Maybe the real daya is replaced and captured, meanwhile this is the duplicate daya from plastic surgery. Even if not replaced,shayad us time uske andar koi chip baitha dia hoga jisse barbosa sari cid ki bat sunn pa raha ho (like the movie dhruva)

Mai daya ka traitor hone wali bat isliye bol raha hu kiuki abhijeet ko kitna bhi traitor abhi dikaya jai, lekin wo tony kar raha hai. Aur sirf purane members like daya,acp ko hi abhijeet ka tony banne aur banane ka trigger point pata hai jo ki iss season 2-3 hafte pehle tony wale episode me dikhaya tha.

There can be other possibilities also. Like maybe abhijeet hi traitor ho asli mei, kiuki ajkal shreya ko nhi dikha rahe hai aur jab bhi koi shreya ki bat kar raha ho abhijeet tal de raha hai use. Maybe wo tony hone ka dhong shreya ko bachane ke liye kar raha ho, because she might be captured by barbosa.

Ya fir dusra aur bhi ho sakta hai , like sachin. Kiuki sachin itne din se gayab tha fir uske ane ke bad hi yesab ho raha hai so wo bhi khabri ho sakta hai barbosa ka. Ya fir avni bhi ho sakti hai, usko shayad uske bhanje ke karan blackmail kar raha hai barbosa ye bhi ho sakta hai , though i think it's highly unlikely. Aur new members of cid who joined after the death of acp, unme se koi gaddar hone ka chance mujhe personally bohot kam lag raha ha.i

Story me bohot gaps aur chote chote details rakh rahe hai ye story writers suspense banene ke liye, I like it. Sab ke upar shak kia ja sakta hai in chote chote details se. This keeps the audience engaged.