Low Tide Ledger

The brief

The summer Athens lit its flame, the ground under this carpet was still open sea, and it stayed that way for years. My clock matches Paris in winter and ignores the summer. Dredgers showed up half a year before Beijing's cauldron. A small office that sells homes, tucked inside a cluster of towers named for five gems that never touched an oyster. Then find my room the way you'd find a bad memory: by the furniture.

• room.jpg, 922 KB

In short

A recovered call hides an Olympic timeline, a time zone and a sea wall, which together point to Eko Atlantic City in Lagos. The lab found the Eko Pearl Towers, the estate agency inside them and, by matching the furniture, the flat behind door plate 3C.

A phone call full of clues

One recovered call and one photo of a living room. The ground was still open sea in the summer of Athens 2004. Dredgers came half a year before Beijing 2008, and the clock sits at UTC+1 all year with no summer time.

Land taken back from the Atlantic

An Atlantic coast at UTC+1 all year rules out Dubai and fits Nigeria. A sea wall of 5 ton concrete blocks, cast on site, now covers the old Bar Beach. That is Eko Atlantic City, reclaimed land in Lagos.

Five pearls that never saw an oyster

Five gems that never touched an oyster are the Eko Pearl Towers, Black, White, Champagne, Indigo and Aqua. The lab placed them on the map and checked the estate agents inside. Nairahomes Realty had photos from the flats.

Matched by the furniture

The agency's listing holds 360 degree photos at 8,192 by 4,096 pixels. Against them the room photo matched on 13 points as given and on 351 once mirrored. It is the view through an open door, flipped.

The plate by the door

At full size the photo shows a glass plate beside that door. It reads 3C, with a divider taller than the digits, so it is not 13C. The agency's own profiles give its name as Nairahomes Realty.

The insight

The room photo was the agency's own 360 degree photo, cropped and mirrored. Flipped back, it matched on 351 points instead of 13.

The flag

hiCTF{Eko-Atlantic-City_Lagos_Nigeria_Nairahomes-Realty_3C}