The Dark Cygnet Files by JE Clarkson

After rescuing Ellen and Johnny Sue from Nemo's experimental hospitals, The Cleaner and Cale find themselves tested as never before. Sammy's appearance after Mai's murder causes confusion and drives a wedge between the members of "The Ghost Society" that threatens to break it apart. This battle of wills, personal losses, and the reappearance of a long-lost family member will drive The Cleaner to the edge. Suddenly, everything she's known before is open to question. Will she find the answers within, "The Dark Cygnet Files"?