It seems she has something she'd like us to investigate.
What could it be?
I've put Sherl in charge of this investigation, and with him in the lead, we've headed to Madame Doublée's residence on Millionaires' Row.
She occupies the largest mansion in the district.
I can't wait to see inside!
It seems Madame Doublée was intending to contact Dad, not me.
But I showed her what I could do, and she's agreed to let me take the case.
Apparently, her beloved pet Rex has gone missing, but Madame was called away before she could tell us more.
In the hunt for the missing Rex, our investigation of Madame Doublée's residence has revealed an incredible number of cat ornaments and trinkets all over the house.
She clearly adores her pet, and must be an avid cat-lover.
We were shown a picture of a magnificent, pure white cat in Madame Doublée's parlour, where Rex spends most of his time.
Sherl deduced that Rex must have slipped on a banana skin and thumbled outside ito the garden.
We're heading there now.
Having followed the trail into the garden, we discovered a shed skin - of a snake or other reptile - and a broken garden gate.
Sherl deduced that Rex, startled by the reptile, bolted out of the hole in the gate.
We must find him and reunite him with his owner!
While investigating near Madame Doublée's residence, we came across a cat, but it doesn't appear to be Rex.
That would be too easy!
Still, we mustn't feel downhearted.
The hunt is still on!
Despite scouring the neighbourhood with Sherl and Ernest, we have yet to find the missing Rex.
Where on Earth can Madame Doublée's beloved pet have got to?
We must find him soon.
The poor woman is beside herself.
When a young girl brought a cat to us we were sure we'd found Rex, but alas, it was the wrong feline.
It's made me realise just how many cats there are around London.
Where can Rex have gone?
I hope he's not going hungry...
We spotted a sure-fire lure for any cat - a fishmonger's van.
But it sped off before we could look inside.
We discovered it comes from a small wharf on the river.
We're heading there now, just in case Rex has ended up there.
Sherl spoke to a stray dog who said that he'd seen a cat that could be Rex.
After jumping out from a boat loaded with bananas, the cat was chased up one of the towers of Tower Bridge by the yapping dog.
It's nearly over.
We just have to catch Rex!
It turns out that Madame Doublée's pet Rex isn't a cat at all.
He's an iguana.
The cat ornaments and everything all around the house are to control where Rex goes.
An unexpected conclusion, but Madame Doubléeis happy at least.