Complex sentence: Liara asks Shepard to meet her at her apartment to discuss plans regarding the location of the Shadow Broker, but when Shepard arrives, the apartment is locked down, and an asari agent Tela Vasir is conducting an investigation into Liara's disappearance.
Split into simpler sentences: Liara asks Shepard to meet her at her apartment to discuss plans regarding the location of the Shadow Broker, but when Shepard arrives, the apartment is locked down. Asari agent Tela Vasir is conducting an investigation into Liara's disappearance.