Just heard today that the first part of the Hawaii Five-0 & NCIS: Los Angeles Cross-Over has just started filming today in Los Angeles. Due to Alex being in rehab at the moment. Daniel Dae Kim will be taking Alex's place alongside Scott Caan instead. Daniel tweeted the news earlier today...
The boys of #H50 are shooting our first day on #NCISLA. Does that make us NCIS:LA 5-0? HCIS:LA? Hmm.#MashUsUp
— Daniel Dae Kim (@danieldaekim) March 13, 2012
Source: Daniel Dae Kim on Twitter