NCIS: Los Angeles 3x21 Touch of Death (2) from Trakt
The joint NCIS: Los Angeles and Hawaii Five-0 task force travel from Hawaii to Los Angeles, when the lead suspect in the case moves to the mainland with a deadly virus in tow. Series crossover part 1 is Hawaii Five-0 (2010) S02E21.

I’m watching NCIS: Los Angeles 3×21 “Touch of Death (2)”

Hawaii Five-0 2x21 Pa Make Loa (Touch of Death) (1) from Trakt
Five-0 and the NCIS: Los Angeles task force team up in Hawaii when there’s a suspect on the loose who is threatening to release a deadly virus into the population. Series crossover part 2 is NCIS: Los Angeles S03E21.

I’m watching Hawaii Five-0 2×21 “Pa Make Loa (Touch of Death) (1)” https://trakt.tv/shows/hawaii-five-0/seasons/2/episodes/21