Between moving, my ongoing divorce and being sick for a week March was pretty much a total loss, and the first half of April wasn't much better. But I've been making progress again these last few weeks, and there seems to be a light at the end of the tunnel.
Hopefully said light isn't an oncoming train.
At any rate, I'm now working on chapter 13 of Perilous Waif. Over the next couple of months I'm going to be posting a series of essays here about the worldbuilding behind this setting, in hopes that if I got the physics completely wrong someone will point out my mistakes before I publish them.
Unfortunately Revenant is still stalled at chapter three. At this point I don't think a summer release is going to happen, although I'm still hoping to get the book out sometime early in the fall. The Daniel Black books are much faster to write than hard SF, and since I have the plot worked out for the next three books now I may just roll on into book five at that point. But no promises there - I've learned that you never know what kind of curve ball life might throw at you next.