The Bundesliga is set for a nerve-shredding finale, and nobody knows that better than Heidenheim. After clawing their way back from the brink, the second-bottom club heads into a must-win showdown against Mainz on Saturday, with survival hanging in the balance.

Coach Frank Schmidt has called for calm in what he describes as a "heart-stopping finale," urging his squad to channel the spirit of last season's great escape. Heidenheim enters the final day level on points with Wolfsburg and St Pauli, but their goal difference leaves them in the drop zone. With two of the three set for relegation and one headed to the playoff, every kick counts.

Adding to the drama, St Pauli faces Wolfsburg in a direct clash. Heidenheim's path is clear: beat Mainz and hope their rivals stumble—ideally with a draw. It's a tall order, but this is a club that thrives on the impossible.

Just two seasons ago, Heidenheim stunned German football by finishing eighth in their debut Bundesliga campaign. Last term, juggling European football proved tougher, but they saved themselves at the death with an injury-time winner in the relegation playoff against Elversberg. Schmidt believes those memories fuel belief. "They have been helping us for a long time," he said Friday, while warning against assuming Mainz has "their heads already half on the beach."

Heidenheim has spent much of this season in the basement, looking doomed just weeks ago. Yet seven points from their last nine available have reignited hope. A win on Saturday could lift them into the relegation playoff against the third-placed team from the second division—if results elsewhere align.

St Pauli, meanwhile, has home advantage against Wolfsburg but shares Heidenheim's goal difference, sitting bottom only on goals scored. Illness and injuries have disrupted their preparations, but coach Alexander Blessin sees fight in his squad. "Training has been really lively," he said Thursday. "It is important for me to see that the team is vibrant and the lads are trying to push each other."

For Wolfsburg, the 2009 champions, the mission is simple. "We know what we have to do," said boss Dieter Hecking. As the Bundesliga prepares for its final act, Heidenheim is ready to write another chapter in its miracle story.