What's on the back of engine, above oil pan? (Wet!)

@PriusCamper your wish came true, unfortunately.

I'm suddenly seeing a pool of wet on the garage floor after each of the last couple of drives. Not oily. No real smell.

I need to find what this is and solve it. We leave on a 4000 mile driving trip in one week.

My main questions:

• what are the (wet) bolts/devices on the back-right side of the engine, above the oil pan, and below-right of exhaust???
• Could the black bolt in photos be loose?! (I've not attempted to change anything.)

Jacked up car. Looking at the back side of the engine I see some wet components, particularly a black bolt, and another wet one above it that's hard to see.

In the photos, "down" is toward the front of the car. I am lying beneath the oil pan, whose attachment bolts are visible in the final photo.

The black bolt "under" the metal plate (and clip for some wire) was quite wet. A lighter bolt above it was dirty/wet. Then in the first two photos you can see a black bolt or cap or ??? that's also glossy/wet.

I'll search for appropriate engine diagrams...

THANK YOU! What an amazing community

 

Hybrid Pitstop replaced my entire engine (with a Gold 2015 rebuilt from ground up) only 30k miles ago.

Is that a likely gasket leak so quickly?