|Scottish Cup fourth round: Rangers v Celtic|
|Venue: Ibrox Stadium, Glasgow Date: Sunday, 18 April Time: 15:00 BST|
|Coverage: Live radio coverage on Sportsound and text commentary on the BBC Sport website & app|
Something's got to give. Rangers have a perfect home record this season, while Celtic are on a history-making Scottish Cup streak.
Only one will be left standing after the Glasgow pair face off on Sunday afternoon, with a quarter-final against St Johnstone awaiting the victors of the eagerly-anticipated tie.
BBC Scotland delves into the main talking points for the fourth Old Firm derby of the season.
- Rangers' Barisic dismisses Celtic 'best team' claim
- Rangers midfielder Jack to miss Euros with Scotland
Can Celtic salvage silverware bid?
Having collected 12 consecutive trophies - the unprecedented quadruple treble - in an era of dominance that shuddered to a halt this season, Celtic are staring at the prospect of ending a campaign empty-handed for the first time since 2010.
The league title - Celtic's property for the last nine years - has gone to Rangers. Should the Scottish Cup also be wrenched from their grasp with defeat to their biggest rivals, it would represent the final insult in a calamitous campaign.
The Parkhead club seek salvation in a competition in which they have won 21 consecutive ties, hoisting the trophy four times in a record sequence. Since the tournament began in 1873, no club had ever won it more than three times in succession.
The last team to beat Celtic in the Scottish Cup? Rangers, in a classic semi-final in April 2016. The rivals shared four goals before the Ibrox side triumphed on penalties in a defining result that ushered in Brendan Rodgers' arrival.
This time Celtic have an interim boss, John Kennedy, and a legendary captain, Scott Brown, who has a maximum eight games left before his 14-year spell at the club ends this summer. Giving Brown his seventh Scottish Cup is the emotional send-off Celtic have set their sights on.
Is Kennedy a contender?
Celtic fans are still holding out for Eddie Howe as manager, but would they settle for Kennedy?
Now seven-and-a-half weeks into his caretaker tenure after filling the void left by Neil Lennon's resignation, he has brought stability and organisation.
Largely gone are the frequent defensive lapses of Lennon's final months, with just a single goal conceded - in last month's 1-1 league draw with Rangers - in Kennedy's unbeaten five games at the helm.
Greater fluency has been instilled in attack too, and Celtic's overall performances have shown gradual improvement since the nerve-ridden 1-0 win over Aberdeen and goalless stalemate at Dundee United, a result which secured the title for Rangers.
It all clicked last weekend as Kennedy's side meted out a 6-0 drubbing to Livingston to ensure they head to Ibrox on the back of their biggest domestic win of the season.
While former Bournemouth boss Howe keeps Celtic hanging after talks, and amid a scarcity of viable alternatives, winning at Ibrox - then retaining the trophy - would strengthen Kennedy's case to stay in post beyond summer.
The harsh truth is the fans would still take plenty of convincing, though. Kennedy is tainted by association, having served on Lennon's staff. He is not the marquee name the supporters crave. Only by winning the cup can he attempt to change that mood.
Are Rangers unbeatable at home?
If Sunday comes down to making home advantage count, Celtic should be worried. Very worried.
Rangers have seen off all-comers at Ibrox in domestic football this season without much hassle. Seventeen league victories, and a Scottish Cup rout of Cove Rangers, make it an 18-match winning run with 53 goals scored and just three conceded.
Celtic have already been dispatched, going down 1-0 in the new year derby when a needless red card for Nir Bitton scuppered their chances.
Indeed, Steven Gerrard's side are just four games from an invincible league campaign, and their only defeat to a Scottish side this season came at St Mirren in the League Cup.
To reach the Scottish Cup last eight, though, they have to overcome the weight of history. In five previous attempts, the Ibrox club have never beaten Celtic at this stage of the tournament.
Can Gerrard's side regain intensity?
After impressively kyboshing Celtic's 10 in a row title bid, for an encore Rangers aim to shatter their rivals' five in a row cup hopes too.
The Premiership became a procession for Gerrard's men, who were 20 points clear and had six games left when crowned champions last month.
Understandably - and almost inevitably - their intensity levels have dipped since the club's first top-flight title in a decade was secured.
When Rangers dispatched St Mirren 3-0 on 6 March - the weekend the title was decided - it was a 15th victory in a 17-game run without defeat across all competitions for Gerrard's side.
They failed to win any of their next three matches, with an away draw and home defeat against Slavia Prague in the Europa League last 16 followed by Old Firm stalemate at Celtic Park.
A cup stroll against Cove followed, before last weekend's 2-1 home win over Hibernian. It set them up nicely for Old Firm battle, but this was not Rangers at their peak.
Hibs' second-half strike, following a consolation for Dundee United in a 4-1 defeat last month, means that of the three Premiership goals conceded at home by Rangers, two have come in their last three Ibrox games.
Rangers have had the upper hand on Celtic this season, winning two and drawing one of their three league meetings.
Can they summon the form that denied Celtic a shot on target back in October? Rangers' 2-0 win at Celtic Park that day set the tone for their Premiership superiority, and is the kind of performance needed to ensure progress.
Who could decide it?
Rangers' Alfredo Morelos is a striker no longer burdened by the anxieties of an Old Firm goal drought. The Colombian's derby equaliser last month was his first goal against Celtic in his 13th game against them.
Morelos plays on the edge and is never far from the spotlight on derby day, as his two card red cards in this combustible fixture attest. He brings a physicality and robust attacking threat that Celtic will have to quell.
Likewise home talisman Ryan Kent. The winger is having the season of his career, with 12 goals and 13 assists, and thrives on the Old Firm occasion.
Celtic's hopes of defeating their great rivals have often been shouldered by Odsonne Edouard. The Frenchman will again be the visitors' attacking focal point, but his burden is lessened with a revitalised Mohamed Elyounoussi, the team's most eye-catching recent performer.
Kennedy revealed time and effort has been spent repairing the Norway forward's battered confidence in recent weeks, and the results are impressive.
The £16m Norway international on loan from Southampton, took his goal tally for the season to 18 with a double against Livingston last Saturday and his versatility makes him difficult to contain.
He has been deployed on the wing, as a 10, and as a striker, and proved adept at each. Having netted his first Old Firm goal last month, Elyounoussi is a man in form for Celtic's date with destiny.