This Idea Would Require DC To Use The Ghost Detectives First

When they were alive, did the Dibnys ever have a detective team-up with Doctor Thirteen? I kind of doubt it, since Ralph and Sue were pretty much mid-tier characters, and the Doc was practically non-existent for a long time, but I figure you can never tell. There was that story in Blue Beetle where Traci whomped Eclipso-housing Jean Loring for what Jean did, and that made it pretty clear Traci had been close with them. Maybe she and her dad were called in on some cases with Ralph and Sue. Or they went to the same investigator conventions.

I do think it would be kind of fun for them to work together now, Ralph and Sue being spirits, and Doctor Thirteen being generally skeptical about such things*. Plus, Traci could come along. I imagine Ralph and Sue would be impressed by her being a sorceress** now, as it strikes me they'd be the cool aunt and uncle, in contrast to her dad's more stuffy, contrarian nature.

Ralph and Sue could show up at crime scene because there's some occult significance to it***, while Doctor 13 is called in by some relative who suspects more base motives (money, fear of past misdeeds being exposed). It turns out they're both right (perhaps the murders would unwittingly bring about the unleashing of some Elder Being), but the fun's hopefully in the process to reach the conclusion, and the solution. If the writer wanted to, having Traci there could provide an excuse for Jaime to tag along, which could lead to the inclusion of Paco and Brenda, or the JLI crew, depending on the preference.

Adding the JLI might make it too crowded, and lead to temptation to write a punch-up, rather than a mystery, but I don't know which group would irritate Doctor 13 more: the teenagers, or the superheroes.

* Reading the end of Azzarello and Chiang's Architecture and Mortality, I think he's more prepared to accept ghosts might exist, in very limited and specific cases, but his default setting is still that it'll be some Scooby-Doo style hoax.

** Would sorceress be an accurate term? "Witch" seemed inadequate, plus it tends to carry negative connotations.

*** I think that happened at the end of 52. I know they were at a crime scene, but I can't recall if there was an occult component to it, like symbols marked in blood on the floor.