This one's reportedly an adventurer, if a young and not notable one, so they send a bit more force, two from the prosecution's office to supervise the two from the Watch with a fifth man hanging back to call in backup. She's staying in the awful Galtan cafe because of course she is. 

The men go in. "Delegate Rivera," he says to the proprietor quietly. "Upstairs?" 

"Excuse me," he says loudly, standing up and moving in such a way as to deniably stand between them and the stairs. "Delegate Rivera? She doesn't stay here." (He is still projecting his voice.) "She just plays here sometimes. I think you're looking in the wrong place."

"Keep your voice down, please. We need to check upstairs."

She can improvise the next bit of her song on the fly to include the verbal components for alter self; before they turn around, she looks like someone who plausibly could have been the person they saw when they came in but definitely doesn't match any descriptions of delegate Rivera on close inspection. She gives Raimon a meaningful glance.

"Do you have any warrant?" His voice is quiet now. "How do I know you're royal officers and not a gang of robbers?"

They indeed have proof of their identities; not anything specific to picking up Rivera, but that they work for the Crown. "Not city watch, either, because I know folks are skittish of them. Is she upstairs?"

"Nobody is," he says, "I'll go with you," to make sure they don't steal anything and to slow them down.

One of them is staring intently at the girl in the corner but she doesn't resemble the sketch at all. Upstairs the four of them go. 

They don't steal anything, just start searching the place thoroughly enough to find an invisible person if there is one.

He'll slow them down if he can, because he hates the police. If he can he'll try to make sure he's between them and the stairs down, but he'll be subtle about it.

And Alicia finishes her song, checks to make sure her money pouch is hidden, and casually walks out the door. Nothing to see here, just another innocent working woman heading back into the city after finishing up her lunch break.

Nope, the fifth guy at the door isn't stupid. "Sorry, ma'am, you've got to stay until they've found who they're looking for." It's a terrible shame about this innocent woman being caught up in this whole business. 

She can very convincingly imitate an innocent bystander who is nevertheless quite intimidated by a sudden soldier!

"I'm so sorry sir, I'll go do that."

And then she hums a little lullaby to quiet her nerves and he can very shortly be a sleeping guy at the door.

Zzzzzzzzz yeah now there's no one to stop her, and a full minute before a pair of the men upstairs come down and realize what happened.

By that time she's long since vacated the premises and wandered unhurriedly into the press of westcrown's streets. She dismisses the alter self now that they've seen its face, and instead wraps her cloak around herself before swearing not to reveal her identity. She takes a meandering path towards a scriviner she once saw in passing to have a letter dictated and sent to the temple of Shelyn telling them to not expect her for the morning channel tomorrow. It's almost certainly a lost cause to try and keep them from having any items of hers, especially since she's not stupid enough to go back for her things, but there's no need to make it easier on them.

"She's not here," Raimon will point out again, after a particularly fruitless search of the upstairs.

" - she made it out the front, damn it, the guard's sleeping."

         "Fucking song-sorcerers."

Then unless they're much quicker on the ball than she expects, about half an hour from the attempted arrest a middle-aged merchant takes a horse and leaves the city towards Hinji. She plans to swing south once she's out of sight and make for the coast, but that's a slightly more unusual destination and might stick around in the memories of the guards for longer.

No, they'll stomp home and tell the wizards. "There's a song-sorcerer on the loose somewhere in the city" is a problem for wizards. 

Well, and they'll smash the rest of the cafe up since he gave them the runaround. Maybe there are hints hiding somewhere about how she assaulted that guard.

Not that they can find! He will immediately report this to a Church of Abadar, accept a truth-telling, write a full description of how they smashed it up after they failed to find the person they were looking for, have them write that it was made under a truth-telling with Detect Magic confirming no spells active, make a copy, have them both notarized, and submit the copy to the Queen, just to make the point that this absolutely doesn't work, at all. Then he'll get back to repairing the cafe.

Look, it was possible the song-sorcerer was invisible and still in the room somewhere. You've got to be thorough when you have a missing suspect who has just assaulted an officer of the law.

The thing is that you've got to track down the runaway delegates before they get to Andoran and become a cause célèbre. Felandriel Morgethai would absolutely put them up in her tower and the people of Andoran protest the heroes who Cheliax tried to jail for telling the truth, never mind that in fact the delegates she's currently charged with tracking down are charged with incitement to violence, arson, and resisting arrest.

Where's Alicia Rivera? Lilia watched her speech; she has a solid recollection to go off.

In a small port town on the coast, currently negotiating for transit on a fishing boat!

How commendably nonstupid of her. Invisibility, Teleport, Flesh to Stone.

Alicia has incredibly good reflexes from long experience of living in terror, which does her precisely no good in avoiding an attack from an invisible wizard 200 feet away. She turns to a statue mid conversation, terrifying her conversation partner.