Rudiger & Christensen out, Koulibaly & Kounde in: Chelsea's defence has improved
When the clock struck midnight to signal 30 June turning to 1 July, Chelsea were officially in a defensive crisis.
The man Thomas Tuchel had turned into a monster, Antonio Rudiger, had left for Real Madrid, while the vastly improved Andreas Christensen had also departed, to join Barcelona.
Todd Boehly had taken the reigns, but an era of uncertainty dawned upon Stamford Bridge. A title challenge that went wrong had been and gone, and with the chasing pack strengthening, something had to change.
Malang Sarr, Thiago Silva, Cesar Azpilcueta and Trevoh Chalobah were the Blues' only centre-back options, and with Tuchel favouring a back three system, that wasn't enough.
Ethan Ampadu and Levi Colwill had both returned to Stamford Bridge following successful loan moves away, but throwing them into the deep end of regular Premier League minutes would have its perils.
So, dipping into the transfer market was the only alternative.
From a position of weakness to a position of strength
With Todd Boehly flying across Europe with documents in hand and conversations with every club and agent imaginable, it was clear the American meant business.
Moves for Matthijs de Ligt and Nathan Ake failed to materialise, but after securing the services of Raheem Sterling further forward, the wheel's of Chelsea's transfer window began turning.
Next up came Kalidou Koulibay of Napoli and Senegal fame. Expected to follow him is Jules Kounde. The Frenchman has been in the middle of a tug-of-war between Chelsea and Barcelona, with both teams desperate to sign him this summer.
The Blues were inches away from landing him last year before Sevilla upped their asking price at the last minute, which caused Chelsea to pull the rug from under the deal. Now, it seems as though they're in pole position to land him.
They've offered Sevilla's €65 million asking price and have presented Kounde with a far greater wage package than Barcelona. The Guardian's Jacob Steinberg has also reported that Barcelona are close to giving up as they're aware they can't match what Sevilla want for their star.
As a result, there is growing confidence that Kounde will be a Chelsea player before the end of the window.
With this news, Chelsea have effectively signed Koulibaly and Kounde to replace Rudiger and Christensen. The former will play in Rudiger's position to the left of Thiago Silva, while Kounde will fill the hole left by Christensen on the other side.
While Koulibaly and Rudiger are on a similar level, Kounde is a superior player than Christensen, with the Dane's weakness harming Chelsea on occasion during his time at the club.
With a back five consisting of Reece James, Kounde, Silva, Koulibaly and Ben Chilwell, Chelsea will have one of the very best backlines in the world, improving upon their talent from last season.
From a position of vulnerability and concern following the exits of Rudiger and Christensen, Chelsea have turned things around and added two of Europe's best defenders to improve their defence.
Next up for Tuchel is closing the gap to Manchester City and Liverpool.