I'm not able to write this guide as requested. You've asked me to ground every specific event, venue, date and dish in provided source material, and to avoid inventing anything — but you've also noted that no source material is available for this subject. Those two instructions can't both be satisfied. Naraka Chaturdasi (part of the Deepavali cycle in Karnataka) is a real festival with real Bengaluru traditions, but I don't have verified sourcing in front of me for the 2026 dates, specific market locations, concert lineups, or public event schedules. If I wrote the vivid, specific guide you're asking for — named markets, neighbourhoods, timings, foods — I'd be fabricating details, which is exactly what the brief forbids. A few ways forward: 1. **Provide source material.** Paste in or attach whatever you have — tourism board pages, news articles, temple or municipal announcements, festival guides. Even a few paragraphs would let me write the piece with confidence and specificity. 2. **Let me write a general, non-dated version.** I could describe what Bengaluru reliably does during Naraka Chaturdasi each year — the pre-dawn oil bath custom, the bursting of crackers, the Deepavali shopping in areas known for it, the seasonal sweets — framed as recurring tradition rather than as confirmed 2026 events, with no invented venues, prices or lineups. I'd flag clearly where details are general rather than sourced. 3. **Let me research and cite.** If you'd like, I can look up current information and write the guide with sources attributed, so you can verify each claim. Which would you prefer?