Complex sentence: They approve a full-scale investigation by Constitutional Protection and invite Blomkvist to a confidential meeting in which they all agree to share information, as well as him being brought on as a special consultant to Edklinth's team.
Split into simpler sentences: They approve a full-scale investigation by Constitutional Protection and invite Blomkvist to a confidential meeting in which they all agree to share information. Blomkvist is brought on as a special consultant to Edklinth's team.