The Champions League returns and with only four teams, the road to fame is open. Each of the remaining pages has a chance, but also question marks that affect their challenge. Can Liverpool break Lionel Messi & Co. to refuse their high altitude attack? And which of the "underdogs" will prevail in the other semi-final?
Here's all you need to know about the superheroes and the sidekicks who can determine the key link for victory.
Jumping to: Tottenham-Ajax | Liverpool-Barcelona
Tottenham Vs. Ajax
WEN: Tuesday, April 30, 3:00 pm ET / 7:00 am BST
BACKSTORY: Ajax makes his glorious past proud after becoming the multi-year A-Series winner of Juventus and Champions League winner Real Madrid has dropped out to enter the semi-finals. The quality, freshness and fearlessness shown in these games has made them the favorites of the neutrals. They are at the top of the Dutch league and in the Dutch Cup final, so they have treble ambitions.
Tottenham has lost more than half of the games he has played since Valentine's Day to third place in the Premier League, beating the mighty Manchester City to come so far. That they are among the last four is notable when you look at the injuries they have suffered ̵
HOW TO TAKE: Tottenham is sometimes more pragmatic, but there are many similarities between the way in which these two teams play, and with the Spurs trio of Toby Alderweireld, Jan Vertonghen and Christian Eriksen There will be few surprises when Ajax spent almost three decades at the youth and senior level.
Given the absence of Kane and the fact that Ajax's approach changes little, it can be imagined (regardless of the pedigree of the opposition) that Spurs are taking advantage of the counterattack, especially with the fleet-footed Lucas Moura.
TOTTENHAM'S STAR TO WATCH: Eriksen. He is at a crossroads in many ways. He has not renewed his contract, which expires in June 2020, suggesting that he is open to a summer train. Would not a decisive turnaround in the Champions League semi-final be the ultimate showcase? He literally faces his past, but he is also the man who can do nothing for Tottenham and must wear it, as he has done so many times before.
AJAX STAR TO WATCH: Frenkie De Jong. He embodies the modern two-way midfielder with the added crease that he wears charisma and a personality well beyond his years. He makes the leap to Barcelona in the summer, but only a few 21-year-olds seem ready for this quantum leap.
X-FACTOR, TOTTENHAM: Dele Alli. He has not given up on the gaudy numbers of past seasons (he scored 22 midfield goals in 2016/17 compared to seven this year), partly because he had missed seven weeks due to injury and partly because he missed out even had to reinvent itself as a hole – Plug in all sorts of jobs where Spurs had a lot of injuries, especially in the middle. But he has the dynamism and selflessness compared to Ajax, and if he can keep Ajax from dominating the midfield, he can point the way of this tottenham.
X-FACTOR, AJAX: David Neres. At 22, he is still very raw, but his dribbling and unpredictability make him a real handful. Within a philosophy that carefully balances the team against the individual, he can occasionally lean towards the latter (which may have been the reason he had a bumpy start to the campaign), but that does not make him less valuable over 180 minutes. 
TOTTENHAM NEEDS … Finds a makeshift combination from the midfield that she can see through (not easy, as Moussa Sissoko and Harry Winks are probably missing) without the Leave initiative to Ajax and bring Eriksen into positions where he can create them.
AJAX NEED TO … Do not drop the intensity and fearlessness simply because Tottenham's pedigree does not match that of their former Champions League opponents (Juventus, Real Madrid and Bayern) The duo of Daley Blind and Matthijs De Ligt has so little to do free-range defense against Lucas Moura as possible.
PREDICTION: Tottenham 2: 1 Ajax. Momentum is not at Tottenham and the midfield is a mystery, but otherwise they do not fit badly against Ajax.
Liverpool Vs. Barcelona
Former Liverpool defender Steve Nicol as the Reds defend themselves against Barcelona's Lionel Messi in the semifinals of the Champions League.
WHEN: Wednesday, May 17, 3:00 pm ET / 7:00 am BST
BACKSTORY: Barcelona won the league on Saturday and will play in the Spanish Cup final towards the end of the month of Valencia. It would be the third time since 2008, a feat considering that this was only achieved three times in the first 40 years of European football.
Liverpool reached the final of the Champions League last year, of course, but unlike then – when they came out of the competition early at home – they are richer with Manchester City for the Premier League title. They have won 10 games in a row in all competitions and look stronger and more complete than last year.
HOW TO PLAY: It was a rarity for a team to score 100 goals in all competitions Liverpool has passed this mark on Saturday and Barcelona in February. Although they are both capable of doing (and doing) a lot, there is a more patient and defensive dimension to what they do. Jurgen Klopp only occasionally drives out with his "Heavy Metal" press and compared to previous incarnations, these Barca pages in the middle of the park are more safety-oriented. The fact that they both have excellent goalkeepers in Marc-Andre ter Stegen and Allisson adds another level of solidity.
BARCELONA'S STAR OF THE WATCH: Lionel Messi. On average, he has more than one goal of a game (again) and plays an even bigger role than before when it comes to falling deeply and creating opportunities for others. Here you will find your own superlatives.
LIVERPOOLS STAR TO CLOCK: Virgil van Dijk. Few signings have been as remodeling in recent years as the arrival of the Dutchman at Anfield in January 2018. A colossus in the air that deals with reading the game and maneuvering a foursome in which both full-backs often attack simultaneously is secondary
X-FACTOR, BARCELONA: Jordi Alba. He has 16 assistants in all competitions this year from the left behind and an almost supernatural understanding with Lionel Messi, who often cuts away from the opposite flank. He will play against Trent Alexander-Arnold and Mo Salah, which means Liverpool will need to bring a midfielder if he progresses. Except that they can not be cocky because Messi is on the other side …
X-FACTOR, LIVERPOOL: Roberto Firmino. He's a center forward who does not score so many goals (he has broken the 20-goal mark only twice in his career), but his amazing movement and his work outside the ball more than make up for it. Between Sergio Busquets in midfield and Gerard Pique in the background, Barcelona will not lose sight of him.
BARCELONA NEEDS … Dictate the game in midfield, beating Alexander-Arnold and Andy Robertson, Liverpool's back-ground, while refusing Salah and Sadio Mane, especially in transition.
LIVERPOOL NEEDS … Always be aware of Messi, but especially if he falls behind to create. Make sure that the front three do not become isolated while maintaining their shape.
PREDICTION: Liverpool 1-2 Barcelona. Two equally aligned sides, but one has Messi, the other not.