Gaius Maro needs to travel faster!

[Kodiak]

For the Dark Brotherhood's Breaching Security quest, you're supposed to assassinate Gaius Maro in a city. But I've been watching him for about 2 weeks of game time, and he never actually enters a city. The problem seems to be that there is not enough time for him to walk and keep to his schedule, so each day he starts out heading toward a destination city, but at midnight the destination changes so he just turns around and heads in a new direction without ever actually reaching anyplace. I don't know if it would be in scope to try to fix this in USSEP, but some solutions might be:

• make him take a carriage/fast travel to the next city each morning so he has time to do his in-city routine before the following morning
• Forget the schedule and just make him go to the city and stay until the next morning regardless of the day
• make him run

[Jebbalon]

Quote

Change of Schedule
Whenever Gaius sees you he begins taking an alternate route. This can make the quest quite hard as he will turn away from a city if he sees you anywhere near it. If this happens, waiting in a tavern in a city on his route will allow him to eventually resume his normal journey.

That is from the UESP page. So, are you sure he is not seeing you?

[BlackPete]

The patch did fix some issues with Gaius' AI packages a long time ago (see this bug ticket). It's been so long since I've done the quest that it's hard to recall for sure what happened in my game, but I do remember it being tricky. For some reason I seem to recall finally catching him at the Bannered Mare in Whiterun. I've read that following him around actually can slow his travel times down as opposed to waiting around in cities he's supposed to be in according to his schedule. While I don't know for certain if that's true or not, I can see him being slowed down if the player follows him on the road since there's the potential that hostile random world encounter events may spawn (dragons, bandits, vampires, etc.) that he otherwise wouldn't run into without the player being nearby.

As far as any further fixes go, I'm not too confident that there's much that can be done. It may be possible to force the game to teleport him to a certain location at given time if he's falling behind schedule, but then that may cause him to suddenly vanish into thin air if you were following him around, which I'd imagine a lot of people may consider "immersion breaking." To the best of my knowledge, there's no function available to make an NPC take a carriage or suddenly start running if they've been delayed for whatever reason. I would suspect that any actions to ensure that an NPC is able to fulfill their set AI functions is already handled internally by the engine and obviously that has its limitations.

[Kodiak]

I read that. I was never actually following him, just watching the objective marker on the map. The only times I was at all close was when he was approaching a city, I would hide inside the city and watch the gates from a distance while hiding so that I could see him enter and watch where he went. But

1. As soon as he reached the gates he turned around and left again. So he never even entered to where he could have seen me. But let's assume he did enter the gates just for a fraction of a second. Just long enough for the AI to get line of sight to where I was hiding. 
2. it was dark, I was sneaking, in shadow, with 100 base stealth +100 stealth enchantments + muffled AND INVISIBLE (Bow of Shadows)
3. So if he "saw" me, it was some kind of scripted event and not legit detection. I never "saw" him rendered inside the gates and my "eye" stayed firmly closed the whole time. 

after watching him do that in both Whiterun and Markarth, I decided to stay away until he actually entered a city. So I just watched his objective marker on the map for another week. He never even got close to any city again. One night I watched him travel from Dawnstar -> High Gate Ruins (was he planning to swim to Solitude?), then turn around and head back toward Fort Fellhammer. After that I gave up. There was no way he would reach Windhelm by midnight. So I used moveto player to place him inside the Windhelm gates. And even though he appeared right on top of me, he didn't see me or try to leave the city but headed toward the Palace of the Kings like he was supposed to.

[Adella]

A solution I have not yet seen here is to change the Time Rate for his journey...and in fact I use 13:1 permanently with no apparent ill effects (Skyrim’s default is 20:1).

The time rate decides how long a Skyrim day takes in our world....but it does not affect the speed the npc moves along a road (or much of anything else as I see).   So a longer day means more time to get where he is going.

Oh and bonus effect...Having longer Skyrim daylight mean you can do a tomb and still get out before nightfall.  However, be aware that very low Time Rate ratios can break your game my 13:1 seems perfectly fine😀

Adella