From the source:
 
Purple Marten stared at the impressive pile paperwork in front her in my Equestria dreamscape. She’d only been gone 4 days but in that time her vast networks of operatives and informants had continued to file their regular reports, or sent her newspaper clippings and magazines articles from around the kingdom that they thought warranted her attention. They had not known she was gone; in fact the changeling had gone to some length to make certain that nopony knew that she’d left Canterlot. Even most of her immediate staff had not been aware that she’d left.  

 
Her plan had succeeded but now she had to get caught back up with how her grand plans had advanced over the last 96 hour. Most of it had carried on like a well-oiled machine in her absence, but once again there were a couple of events from the palace that disturbed and confused her.
 
First was the events surrounding Last Thing. Yes Purple Marten was happy to see one of Celestia’s most competent and dangerous operatives disabled. There was much about Last Thing’s abilities that was still speculation for her, and despite her efforts she’d been unable to get an operative in on the Time Anchor team  
or persuade one of them to divulge anything useful about nature of that device or the pony so closely tied to it.
 
However based on reports from eyewitnesses the Mare-in-Waiting had apparently succumbed to profound encounter with somepony/or something after an uncontrolled journey into the future. The mare had screamed about needing to stop a gatekeeper before they unleashed some horror upon the world. A horror so great that it had broken the mind of a hardened veteran.
 
Purple Marten stared at this report and wondered. Was there connection between this recent event and the death Lucky Card just a couple weeks ago?
 
Once again the changeling speculated whether there was a third, potentially very deadly, party that was advancing their own plans? Or was this possibly another faction? A fourth player that was beginning to wield influence.  
To make matters worse her vast network had not been able to determine the exact nature of who this first or possibly second faction was. Although there was a growing suspicion that the answer might be found in nearby farming community of Ponyville. There had been some unusual activities around it in the past year. So she was arranging to have several operatives assigned to the area.
 
The other piece of information that made her pause was a report from Drone 992/Corporal Trotter. The drone had apparently impressed his commanding officer enough that he was going to recommend the corporal for a promotion and even try to have him placed in the officer’s training program.
 
This did have its advantages since it further casted the corporal as a model soldier, and made it even harder for Celestia’s Mares-in-Waiting to justify investigating such an outstanding member of the Royal Guard.
 
At the same time she was a little concerned about last few comments in Drone 992’s most recent report. He commented that he was genuinely surprised and honored that he was carrying out his role so well that ponies would consider him for a promotion. This made Marten uneasy. The last thing she needed was for him to start having divided loyalties. No matter how small the chance. Drone 992 was the head architect behind the operation to capture Princess Cadence. The operation was too far along to consider bringing in another changeling, or changelings, to pick up the pieces or start over again.
 
However as she thought about it a devilish smile slowly grew on her face. She did have one card she could play that she would almost guarantee his continued, and absolute, loyalty. She’d been planning on to implement it soon, but now she would push it forward even sooner. Softly she purred.
 
“Yes Drone 992. I am going to give you a reward like you’ve never had before!”
 
To be continued.

Check the source, OP. It’s an OC and one hell of a description.